

<!-- RR Donnelley Xcelerate Instance Document, based on XBRL 2.1  http://www.rrdonnelley.com/ -->
<!-- Version:  6.21.0 -->
<!-- Round: 10 -->
<!-- Creation date: 2014-05-13T19:21:09Z -->
<!-- Copyright (c) 2005-2013 R.R. Donnelley & Sons Company All Rights Reserved. -->
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 &lt;table style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; BORDER-COLLAPSE: collapse" cellspacing="0" cellpadding="0" width="100%" border="0"&gt;
 &lt;tr&gt;
 &lt;td valign="top" width="4%" align="left"&gt;&lt;b&gt;6.&lt;/b&gt;&lt;/td&gt;
 &lt;td valign="top" align="left"&gt;&lt;b&gt;Stock-based compensation and
 warrants&lt;/b&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;/table&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 6pt; TEXT-INDENT: 4%"&gt;
 In 2013, the Company&amp;#x2019;s board of directors and stockholders
 approved the 2013 Stock Option and Incentive Plan (&amp;#x201C;2013
 Plan&amp;#x201D;) which allows for the granting of incentive stock
 options, non-qualified stock options, restricted stock awards, as
 well as other equity awards to the Company&amp;#x2019;s employees,
 members of the board of directors and consultants of the Company.
 The 2013 Plan replaced the 2010 Stock Option and Grant Plan. In
 January 2014, the number of shares of common stock available for
 issuance under the 2013 Plan was increased by 960 shares as a
 result of the automatic increase provision of the 2013 Plan. As of
 March&amp;#xA0;31, 2014, the total number of shares of common stock
 available for issuance under the 2013 Plan was 964.&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 18pt"&gt;
 &lt;b&gt;&lt;i&gt;Stock-based compensation expense&lt;/i&gt;&lt;/b&gt;&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 6pt; TEXT-INDENT: 4%"&gt;
 Stock-based compensation expense by award type was as follows:&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 12pt; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;table style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; BORDER-COLLAPSE: collapse" cellspacing="0" cellpadding="0" width="76%" align="center" border="0"&gt;
 &lt;tr&gt;
 &lt;td width="76%"&gt;&lt;/td&gt;
 &lt;td valign="bottom" width="8%"&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td valign="bottom" width="8%"&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 8pt; FONT-FAMILY: Times New Roman"&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="6" align="center"&gt;
 &lt;b&gt;Three&amp;#xA0;months&amp;#xA0;ended&amp;#xA0;March&amp;#xA0;31,&lt;/b&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 8pt; FONT-FAMILY: Times New Roman"&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;&lt;b&gt;2014&lt;/b&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;&lt;b&gt;2013&lt;/b&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; TEXT-INDENT: -1em"&gt;
 Stock options&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;2,477&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;639&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; TEXT-INDENT: -1em"&gt;
 Restricted stock awards&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;16&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;22&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 1px"&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 1px solid"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 1px solid"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 1px solid"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 1px solid"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;font style="FONT-SIZE: 8pt"&gt;&amp;#xA0;&amp;#xA0;&lt;/font&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;2,493&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;font style="FONT-SIZE: 8pt"&gt;&amp;#xA0;&amp;#xA0;&lt;/font&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;661&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 1px"&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;/table&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 12pt; TEXT-INDENT: 4%"&gt;
 As of March&amp;#xA0;31, 2014, there was $20,430 of unrecognized
 stock-based compensation expense related to unvested stock options
 and restricted stock awards that is expected to be recognized over
 a weighted-average period of 3.2 years.&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 12pt; TEXT-INDENT: 4%"&gt;
 During the three months ended March&amp;#xA0;31, 2014, the Company
 issued 2 shares of restricted common stock in exchange for
 consulting services. The shares vested upon issuance and the
 Company recognized $42 of expense related to the services
 provided.&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 12pt; TEXT-INDENT: 4%"&gt;
 During the three months ended March&amp;#xA0;31, 2014, 123 options held
 by former employees were modified to extend the expiration date.
 The modification was valued using a Black-Scholes option valuation
 model and the Company accounted for the $643 of incremental value
 within general and administrative expense.&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0px; FONT-SIZE: 1px; MARGIN-TOP: 18px"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 0pt"&gt;
 &lt;b&gt;&lt;i&gt;Restricted common stock&lt;/i&gt;&lt;/b&gt;&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 12pt; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;table style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; BORDER-COLLAPSE: collapse" cellspacing="0" cellpadding="0" width="76%" align="center" border="0"&gt;
 &lt;tr&gt;
 &lt;td width="74%"&gt;&lt;/td&gt;
 &lt;td valign="bottom" width="10%"&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td valign="bottom" width="10%"&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 8pt; FONT-FAMILY: Times New Roman"&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;&lt;b&gt;Shares&lt;/b&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;&lt;b&gt;&lt;font style="WHITE-SPACE: nowrap"&gt;Weighted-average&lt;/font&gt;&lt;br /&gt;
 grant date&lt;/b&gt;&lt;br /&gt;
 &lt;b&gt;fair value&lt;/b&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; TEXT-INDENT: -1em"&gt;
 Unvested balance at December&amp;#xA0;31, 2013&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;69&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;0.95&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 3em; TEXT-INDENT: -1em"&gt;
 Granted&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap" align="right"&gt;
 &amp;#x2014;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap" align="right"&gt;
 &amp;#x2014;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 3em; TEXT-INDENT: -1em"&gt;
 Vested&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;(21&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;)&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;0.95&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 3em; TEXT-INDENT: -1em"&gt;
 Forfeited&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap" align="right"&gt;
 &amp;#x2014;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap" align="right"&gt;
 &amp;#x2014;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 1px"&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 1px solid"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 1px solid"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 1px solid"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 1px solid"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; TEXT-INDENT: -1em"&gt;
 Unvested balance at March 31, 2014&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;font style="FONT-SIZE: 8pt"&gt;&amp;#xA0;&amp;#xA0;&lt;/font&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;48&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;font style="FONT-SIZE: 8pt"&gt;&amp;#xA0;&lt;/font&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;0.95&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 1px"&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;/table&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 18pt"&gt;
 &lt;b&gt;&lt;i&gt;Stock options&lt;/i&gt;&lt;/b&gt;&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 6pt; TEXT-INDENT: 4%"&gt;
 The following table summarizes the stock option activity under the
 Company&amp;#x2019;s equity award plans:&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 12pt; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;table style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; BORDER-COLLAPSE: collapse" cellspacing="0" cellpadding="0" width="76%" align="center" border="0"&gt;
 &lt;tr&gt;
 &lt;td width="81%"&gt;&lt;/td&gt;
 &lt;td valign="bottom" width="5%"&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td valign="bottom" width="5%"&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 8pt; FONT-FAMILY: Times New Roman"&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;&lt;b&gt;Shares&lt;/b&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;&lt;b&gt;Weighted-&lt;br /&gt;
 average&lt;br /&gt;
 exercise&lt;br /&gt;
 price&lt;/b&gt;&lt;br /&gt;
 &lt;b&gt;per share&lt;/b&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; TEXT-INDENT: -1em"&gt;
 Outstanding at December&amp;#xA0;31, 2013&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;3,958&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;5.21&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 3em; TEXT-INDENT: -1em"&gt;
 Granted&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;724&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;23.87&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 3em; TEXT-INDENT: -1em"&gt;
 Exercised&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;(322&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;)&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;2.22&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 3em; TEXT-INDENT: -1em"&gt;
 Canceled or forfeited&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;(37&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;)&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;5.21&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 1px"&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 1px solid"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 1px solid"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; TEXT-INDENT: -1em"&gt;
 Outstanding at March&amp;#xA0;31, 2014&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;font style="FONT-SIZE: 8pt"&gt;&amp;#xA0;&amp;#xA0;&lt;/font&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;4,323&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;font style="FONT-SIZE: 8pt"&gt;&amp;#xA0;&lt;/font&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;8.56&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 1px"&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; TEXT-INDENT: -1em"&gt;
 Exercisable at March&amp;#xA0;31, 2014&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;font style="FONT-SIZE: 8pt"&gt;&amp;#xA0;&amp;#xA0;&lt;/font&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;1,442&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;font style="FONT-SIZE: 8pt"&gt;&amp;#xA0;&lt;/font&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;2.86&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 1px"&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; TEXT-INDENT: -1em"&gt;
 Vested and expected to vest at March&amp;#xA0;31, 2014&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;font style="FONT-SIZE: 8pt"&gt;&amp;#xA0;&amp;#xA0;&lt;/font&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;4,240&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;font style="FONT-SIZE: 8pt"&gt;&amp;#xA0;&lt;/font&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;8.50&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 1px"&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;/table&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 12pt; TEXT-INDENT: 4%"&gt;
 Options exercisable for 322 shares of common stock were exercised
 during the three months ended March&amp;#xA0;31, 2014, resulting in
 total proceeds to the Company of $572. In accordance with the stock
 option plans, the shares were issued from a pool of shares reserved
 for issuance under the stock option plans described above.&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 18pt"&gt;
 &lt;b&gt;&lt;i&gt;Employee stock purchase plan&lt;/i&gt;&lt;/b&gt;&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 6pt; TEXT-INDENT: 4%"&gt;
 On June&amp;#xA0;3, 2013, the Company&amp;#x2019;s board of directors
 adopted its 2013 Employee Stock Purchase Plan (&amp;#x201C;2013
 ESPP&amp;#x201D;), which was subsequently approved by its stockholders
 and became effective upon the closing of the Company&amp;#x2019;s
 initial public offering on June&amp;#xA0;24, 2013. The 2013 ESPP
 authorizes the initial issuance of up to a total of 238 shares of
 the Company&amp;#x2019;s common stock to participating employees. As of
 March&amp;#xA0;31, 2014, the first offering under the 2013 ESPP has not
 occurred.&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 18pt"&gt;
 &lt;b&gt;&lt;i&gt;Warrants&lt;/i&gt;&lt;/b&gt;&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 6pt; TEXT-INDENT: 4%"&gt;
 As of March&amp;#xA0;31, 2014 and December&amp;#xA0;31, 2013, the Company
 had 338 warrants outstanding to purchase common stock. During the
 three months ended March&amp;#xA0;31, 2014, there were no warrants
 exercised and no cancellations or expirations.&lt;/p&gt;
 &lt;/div&gt;</us-gaap:DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock>
  <us-gaap:NumberOfOperatingSegments contextRef="eol_PE639928--1410-Q0002_STD_90_20140331_0" unitRef="Segment" decimals="INF" id="id_4932441_D899C0D1-2DC5-437A-92E2-A419079BD1C3_1_0">1</us-gaap:NumberOfOperatingSegments>
  <us-gaap:CommitmentsAndContingenciesDisclosureTextBlock contextRef="eol_PE639928--1410-Q0002_STD_90_20140331_0" id="id_4932441_44FE9413-11FB-4C72-949D-1B6233A6ED15_1_0">&lt;div&gt;
 &lt;table style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; BORDER-COLLAPSE: collapse" cellspacing="0" cellpadding="0" width="100%" border="0"&gt;
 &lt;tr&gt;
 &lt;td valign="top" width="4%" align="left"&gt;&lt;b&gt;4.&lt;/b&gt;&lt;/td&gt;
 &lt;td valign="top" align="left"&gt;&lt;b&gt;Commitments and
 contingencies&lt;/b&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;/table&gt;
 &lt;!-- xbrl,body --&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 6pt; TEXT-INDENT: 4%"&gt;
 On June&amp;#xA0;3, 2013, the Company entered into a nine-year building
 lease for approximately 43,600 square feet of space for its new
 corporate headquarters at 150 Second Street, Cambridge,
 Massachusetts, which commenced in December 2013. The lease has
 monthly lease payments of $209 the first 12 months with annual rent
 escalations thereafter and provides a rent abatement of $209 per
 month for the first six months. The Company has the option to
 extend this lease by an additional five years. As the Company
 obtained access to the newly leased space on July&amp;#xA0;22, 2013 in
 order to begin the build-out, this is considered the lease
 commencement date for accounting purposes, thus rent expense began
 on this date and will be recognized on a straight-line basis over
 the term of the lease. In addition, the lease provides a
 contribution from the landlord towards the initial build-out of the
 space of up to $6,538. The Company capitalizes the leasehold
 improvements as property and equipment and records the landlord
 incentive payments received as deferred rent and amortizes these
 amounts as reductions to rent expense over the lease term. In
 accordance with the lease, the Company entered into a
 cash-collateralized irrevocable standby letter of credit in the
 amount of $1,253, naming the landlord as beneficiary. This letter
 of credit may be reduced to $1,044, $835, and $627 upon the rent
 commencement date and the first and second anniversaries of the
 rent commencement date, respectively. The Company relocated into
 its new corporate headquarters in December 2013 and ceased use of
 its former facility during the first quarter of 2014. During the
 first quarter of 2014, the Company fully subleased its former
 facility, which decreased the rent abatement available under its
 new lease. The lease for the Company&amp;#x2019;s former headquarters,
 located at 840 Memorial Drive, Cambridge, Massachusetts, expires on
 March&amp;#xA0;31, 2015.&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 12pt; TEXT-INDENT: 4%"&gt;
 The Company is party to various agreements, principally relating to
 licensed technology, that require future payments relating to
 milestones not met at March&amp;#xA0;31, 2014 and December&amp;#xA0;31,
 2013 or royalties on future sales of specified products.&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 12pt; TEXT-INDENT: 4%"&gt;
 The Company enters into standard indemnification agreements in the
 ordinary course of business. Pursuant to the agreements, the
 Company indemnifies, holds harmless, and agrees to reimburse the
 indemnified party for losses suffered or incurred by the
 indemnified party, generally the Company&amp;#x2019;s business partners
 or customers, in connection with claims by any third party with
 respect to the Company&amp;#x2019;s products or business activities. The
 term of these indemnification agreements is generally perpetual any
 time after execution of the agreement. The maximum potential amount
 of future payments the Company could be required to make under
 these indemnification agreements is unlimited. The Company has
 never incurred costs to defend lawsuits or settle claims related to
 these indemnification agreements.&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 12pt; TEXT-INDENT: 4%"&gt;
 The Company&amp;#x2019;s wholly-owned subsidiary bluebird bio France,
 SARL participates in the French Cr&amp;#xE9;dit d&amp;#x2019;Imp&amp;#xF4;t
 Recherche (&amp;#x201C;CIR&amp;#x201D;) program which allows companies to
 monetize up to 30% of eligible research expenses. The Company
 received aggregate reimbursement of $807 related to 2010, 2011 and
 2012. The Company recognized these amounts as reductions to
 research and development expense in the periods incurred. The years
 2010 through 2013 are open and subject to examination. The Company
 has applied for $873 related to 2013 and has not yet applied for
 $269 related to the first quarter of 2014 which are classified as a
 current and non-current receivables, respectively, on the
 accompanying balance sheets as of March 31, 2014. The Company
 received a notice from the Minist&amp;#xE8;re de l&amp;#x2019;Enseignement
 Sup&amp;#xE9;rieur et de la Recherche in March 2014 inquiring of the
 Company regarding the eligibility of such research expenses
 pursuant to the CIR program. Based on the nature of the research
 activities conducted by bluebird bio France, SARL, the Company has
 concluded that it is probable that these receivables are
 collectable. However, any adjustment as a result of the inquiry
 would result in a refund of the amounts previously received or
 impairment of the Company&amp;#x2019;s receivable.&lt;/p&gt;
 
 
 &lt;/div&gt;</us-gaap:CommitmentsAndContingenciesDisclosureTextBlock>
  <us-gaap:CollaborativeArrangementDisclosureTextBlock contextRef="eol_PE639928--1410-Q0002_STD_90_20140331_0" id="id_4932441_645E485A-CEBF-4443-B634-0F368E7DFD76_1_0">&lt;div&gt;
 &lt;table style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; BORDER-COLLAPSE: collapse" cellspacing="0" cellpadding="0" width="100%" border="0"&gt;
 &lt;tr&gt;
 &lt;td valign="top" width="4%" align="left"&gt;&lt;b&gt;5.&lt;/b&gt;&lt;/td&gt;
 &lt;td valign="top" align="left"&gt;&lt;b&gt;Significant agreements&lt;/b&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;/table&gt;
 &lt;!-- xbrl,body --&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 6pt"&gt;
 &lt;b&gt;&lt;i&gt;Celgene Corporation&lt;/i&gt;&lt;/b&gt;&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 4%; MARGIN-TOP: 6pt"&gt;
 &lt;i&gt;Summary of the Collaboration Agreement&lt;/i&gt;&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 6pt; TEXT-INDENT: 4%"&gt;
 On March&amp;#xA0;19, 2013, the Company entered into a Master
 Collaboration Agreement (the &amp;#x201C;Collaboration Agreement&amp;#x201D;)
 with Celgene to discover, develop and commercialize potentially
 disease-altering gene therapies in oncology. The collaboration is
 focused on applying gene therapy technology to genetically modify a
 patient&amp;#x2019;s own T cells, known as chimeric antigen receptor, or
 CAR, T cells, to target and destroy cancer cells. Additionally, on
 March&amp;#xA0;19, 2013, the Company entered into a Platform Technology
 Sublicense Agreement (the &amp;#x201C;Sublicense Agreement&amp;#x201D;) with
 Celgene pursuant to which the Company obtained a sublicense to
 certain intellectual property from Celgene, originating under
 Celgene&amp;#x2019;s license from Baylor College of Medicine, for use in
 the collaboration.&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 12pt; TEXT-INDENT: 4%"&gt;
 Under the terms of the Collaboration Agreement, the Company
 received a $75,000 up-front, non-refundable cash payment. The
 Company will be responsible for conducting discovery, research and
 development activities through completion of Phase I clinical
 studies, if any, during the initial term of the agreement, or three
 years. The collaboration will be governed by a joint steering
 committee (&amp;#x201C;JSC&amp;#x201D;) formed by an equal number of
 representatives from the Company and Celgene. The JSC will, among
 other activities, review the collaboration program, review and
 evaluate product candidates and approve regulatory plans. In
 addition to the JSC, the Collaboration Agreement provides that the
 Company and Celgene will each appoint representatives to establish
 a patent committee, which will be responsible for managing the
 intellectual property developed and used during the
 collaboration.&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 12pt"&gt;
 &amp;#xA0;&amp;#xA0;&amp;#xA0;&amp;#xA0;&amp;#xA0;&amp;#xA0;&amp;#xA0;&amp;#xA0;Prior to expiration
 of the initial term of the Collaboration Agreement, Celgene has two
 options to extend the term, through March&amp;#xA0;19, 2019, with the
 payment of significant extension fees. Separately, Celgene has an
 option to license an unlimited number of product candidates
 resulting from the collaboration during a period commencing upon
 execution of the Collaboration Agreement and continuing through a
 specified period following the completion of Phase I clinical
 studies for each individual product candidate. In the event such
 option is exercised, the Company would grant Celgene an exclusive
 worldwide license to develop and commercialize such product
 candidate. Upon exercise of the option to license a product
 candidate, Celgene is required to pay an option fee, which is
 subject to reduction if the Company elects to co-develop and
 co-promote such product candidate in the United States. For any
 product candidates licensed by Celgene, the Company may be
 responsible, at Celgene&amp;#x2019;s election, to continue performing
 certain development activities contemplated as part of the
 collaboration plan. If Celgene does not exercise its option with
 respect to a product candidate prior to the expiration of the
 applicable option period (each a &amp;#x201C;declined product
 candidate&amp;#x201D;), then the Company has the right to develop the
 product candidate outside the scope of the collaboration, subject
 to a Celgene opt-in right to obtain a license to that declined
 product candidate for significant additional cash consideration.
 The opt-in right exists through a specified period following the
 completion of a pivotal study for the specific declined product
 candidate and functions in the same manner as the option to license
 any other product candidates resulting from the collaboration.&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 12pt; TEXT-INDENT: 4%"&gt;
 In addition, Celgene would be required to make certain milestone
 payments upon the achievement of specified clinical, regulatory and
 commercial events. For each product candidate that is licensed by
 Celgene, the Company would be eligible to receive per product up to
 $20,000 in option fees, up to $10,000 in clinical milestone
 payments, up to $117,000 in regulatory milestone payments and up to
 $78,000 in commercial milestone payments. Clinical milestone
 payments are triggered upon initiation of a defined phase of
 clinical research for a product candidate. Regulatory milestone
 payments are triggered upon approval to market a product candidate
 by the FDA or other global regulatory authorities. Commercial
 milestone payments are triggered upon the first commercial sale of
 an approved pharmaceutical product and when an approved
 pharmaceutical product reaches certain defined levels of net sales
 by the licensee or receives approval to be marketed by certain
 global regulatory authorities in a specified number of countries
 outside of the United States. In addition, to the extent any of the
 product candidates licensed by Celgene are commercialized, the
 Company would be entitled to receive tiered royalty payments
 ranging from the mid-single digits to mid-teens based on a
 percentage of net sales. Royalty payments are subject to certain
 reductions, including for any royalty payments required to be made
 by Celgene to acquire patent rights, with an aggregate minimum
 floor. The Company is not eligible to receive either milestone
 payments or royalty payments unless and until Celgene exercises its
 option to license a product candidate resulting from the
 collaboration whereupon the parties will execute a license
 agreement, the terms of which are included as part of the
 collaboration arrangement.&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 12pt; TEXT-INDENT: 4%"&gt;
 Additionally, the Company may elect to co-develop and co-promote
 product candidates licensed by Celgene. If the Company elects to
 co-develop and co-promote a product candidate, then the parties
 would share equally in all costs incurred relating to the
 development, commercialization and manufacture of the product
 candidate within the United States and share equally in the profits
 generated by such product candidate in the United States.
 Additionally, if the Company elects to co-develop and co-promote a
 product candidate, then the option fees, milestones and royalties
 would decrease compared to those described above. Under this
 scenario, the Company would receive per product up to $10,000 in
 option fees, up to $10,000 in clinical milestone payments and
 outside of the United States, up to $54,000 in regulatory milestone
 payments and up to $36,000 in commercial milestone payments.
 Clinical milestone payments are triggered upon initiation of a
 defined phase of clinical research for a product candidate.
 Regulatory milestone payments are triggered upon approval to market
 a product candidate by global regulatory authorities. Commercial
 milestone payments are triggered when an approved pharmaceutical
 product reaches certain defined levels of net sales by the licensee
 or receives approval to be marketed by certain global regulatory
 authorities in a specified number of countries outside the United
 States. In addition, to the extent any of the product candidates
 licensed by Celgene and co-developed and co-promoted by the Company
 are commercialized, the Company would be entitled to receive tiered
 royalty payments ranging from the mid-single digits to mid-teens
 based on a percentage of net sales from sales generated outside of
 the United States. Royalty payments are subject to certain
 reductions, including for any royalty payments required to be made
 by Celgene to acquire patent rights, with an aggregate minimum
 floor. The Company is not eligible to receive profit share
 payments, milestone payments or royalty payments unless and until
 Celgene exercises its option to license a product candidate
 resulting from the collaboration whereupon the parties will execute
 a co-development, co-promote and profit share agreement, the terms
 of which are included as part of the collaboration arrangement.&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 12pt; TEXT-INDENT: 4%"&gt;
 In the event Celgene elects to license a product candidate
 discovered and developed as part of the Collaboration Agreement,
 Celgene would be solely responsible for all costs and expenses of
 manufacturing and supplying any product candidates. Subject to
 customary back-up supply rights granted to Celgene, the Company has
 the sole right to manufacture or have manufactured supplies of
 vectors and associated payloads manufactured for incorporation into
 the associated product candidate. Celgene would reimburse the
 Company for the costs incurred to manufacture and supply such
 vectors and associated payloads, plus a modest mark-up. The Company
 is not obligated to manufacture or have manufactured supplies of
 vectors and associated payloads for incorporation into an optioned
 product candidate unless and until Celgene exercises its option to
 license a product candidate resulting from the collaboration
 whereupon the parties will execute a separate manufacturing and
 supply agreement.&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 12pt; TEXT-INDENT: 4%"&gt;
 The Collaboration Agreement may be terminated by either the Company
 or Celgene, upon written notice, in the event of the other
 party&amp;#x2019;s uncured material breach. Celgene may terminate the
 Collaboration Agreement for any reason upon written notice to the
 Company. If the Collaboration Agreement is terminated, rights to
 product candidates in development at the time of such termination
 will be allocated to the parties through a mechanism included in
 the Collaboration Agreement. In addition, if Celgene terminates the
 Collaboration Agreement as a result of a breach by the Company,
 then any then-existing co-development and co-promotion agreement
 will be automatically terminated and replaced with a license
 agreement for such product candidate and any amounts payable by
 Celgene under any then-existing product license agreements will be
 reduced.&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 4%; MARGIN-TOP: 18pt"&gt;
 &lt;i&gt;Call Option&lt;/i&gt;&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 6pt; TEXT-INDENT: 4%"&gt;
 During the initial three-year term of the collaboration and, if
 extended, during the first two-year extension term of the
 collaboration, in the event that the Company engages in a change in
 control transaction, including for such purposes a merger or
 consolidation of the Company or the sale of all or substantially
 all of the Company&amp;#x2019;s assets, or if another person or entity
 or group of persons or entities acquires at least 50% of the
 Company&amp;#x2019;s voting capital stock, then Celgene has the right,
 but not the obligation, to terminate the Collaboration Agreement
 and obtain perpetual, non-terminable, worldwide, exclusive, fully
 paid-up licenses to all, but not less than all, of the product
 candidates previously identified under the Collaboration Agreement
 (the &amp;#x201C;Call Option&amp;#x201D;). Under the Call Option, the product
 candidates to which Celgene would have the right to acquire
 licenses include any product candidate previously licensed out of
 the collaboration during the term of the collaboration, any product
 candidate for which the Company has exercised the right to
 co-develop and co-promote within the United States, any product
 candidate for which Celgene previously declined its option to
 obtain a license and any product candidate for which at least &lt;i&gt;in
 vivo&lt;/i&gt; efficacy studies have been initiated or authorized by the
 JSC. The purchase price for such licenses would be based on the
 fair value of these rights received and obligations assumed
 determined pursuant to a binding arbitration process.&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0px; FONT-SIZE: 1px; MARGIN-TOP: 12px"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 0pt; TEXT-INDENT: 4%"&gt;
 In addition, during the initial three-year term of the
 collaboration, but not during any extension term, in the event that
 Celgene exercises the Call Option, in addition to the right to
 acquire the fully paid-up licenses described above, Celgene would
 obtain a perpetual, non-terminable, worldwide, exclusive license to
 the Company&amp;#x2019;s intellectual property to develop one or more
 CAR T cell products targeting one or more oncology associated
 target antigens for the remainder of the initial collaboration
 term. Following the initial collaboration term, the license to the
 Company&amp;#x2019;s intellectual property is limited to target antigens
 identified by Celgene promptly following the initial collaboration
 term for which Celgene reasonably intends to develop CAR T cell
 products. There is no limit to the number of oncology-related
 target antigens Celgene may select under this license. Upon
 commercialization of any such product candidate so licensed by
 Celgene, Celgene would be obligated to pay the Company a specified
 milestone payment upon regulatory approval and a percentage of net
 sales as a royalty.&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 12pt; TEXT-INDENT: 4%"&gt;
 The Company concluded that the value of the Call Option is
 immaterial based primarily on the probability that the Call Option
 would become exercisable.&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 4%; MARGIN-TOP: 18pt"&gt;
 &lt;i&gt;Accounting Analysis&lt;/i&gt;&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 6pt; TEXT-INDENT: 4%"&gt;
 The Company&amp;#x2019;s arrangement with Celgene contains the following
 deliverables: (i)&amp;#xA0;discovery, research and development
 services, (ii)&amp;#xA0;participation on the JSC and
 (iii)&amp;#xA0;participation on the patent committee. The Company has
 determined that the options to extend the term of the agreement and
 the options to license product candidates, including those related
 to Celgene&amp;#x2019;s opt-in right for a declined product candidate,
 are substantive options. Celgene is not contractually obligated to
 exercise the options. Additionally, as a result of the uncertain
 outcome of the discovery, research and development activities, the
 Company is at risk with regard to whether Celgene will exercise the
 options. Moreover, the Company has determined that the options are
 not priced at a significant and incremental discount. Accordingly,
 the options are not considered deliverables at the inception of the
 arrangement and the associated option fees are not included in
 allocable arrangement consideration. The Company has determined
 that the potential obligation to manufacture or have manufactured
 supplies of vectors and associated payloads for incorporation into
 an optioned product candidate is contingent upon Celgene exercising
 its option to license a product candidate resulting from the
 collaboration. Therefore, consistent with the treatment of the
 options to license product candidates, the Company&amp;#x2019;s
 potential obligation under a manufacturing and supply agreement is
 not considered a deliverable at the inception of the arrangement
 and the associated fees are not included in allocable arrangement
 consideration.&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 12pt; TEXT-INDENT: 4%"&gt;
 The Company concluded that each of the three deliverables
 identified at the inception of the arrangement (discovery, research
 and development services, participation on the JSC and
 participation on the patent committee) has standalone value from
 the other undelivered elements. Additionally, the Collaboration
 Agreement does not include return rights related to the initial
 collaboration term. Accordingly, each deliverable qualifies as a
 separate unit of accounting.&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 12pt; TEXT-INDENT: 4%"&gt;
 The Company identified the allocable arrangement consideration as
 the $75,000 up-front payment. The Company determined that each of
 the identified deliverables have the same period of performance
 (the three year initial term) and have the same pattern of revenue
 recognition, ratably over the period of performance. As a result,
 the $75,000 arrangement consideration will be recognized over the
 three year initial term.&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 12pt; TEXT-INDENT: 4%"&gt;
 The Company evaluated all of the milestones that may be received in
 connection with Celgene&amp;#x2019;s option to license a product
 candidate resulting from the collaboration. In evaluating if a
 milestone is substantive, the Company assesses whether:
 (i)&amp;#xA0;the consideration is commensurate with either the
 Company&amp;#x2019;s performance to achieve the milestone or the
 enhancement of the value of the delivered item(s) as a result of a
 specific outcome resulting from the Company&amp;#x2019;s performance to
 achieve the milestone, (ii)&amp;#xA0;the consideration relates solely
 to past performance and (iii)&amp;#xA0;the consideration is reasonable
 relative to all of the deliverables and payment terms within the
 arrangement. All clinical and regulatory milestones are considered
 substantive on the basis of the contingent nature of the milestone,
 specifically reviewing factors such as the scientific, clinical,
 regulatory, commercial and other risks that must be overcome to
 achieve the milestone as well as the level of effort and investment
 required. Accordingly, such amounts will be recognized as revenue
 in full in the period in which the associated milestone is
 achieved, assuming all other revenue recognition criteria are met.
 All commercial milestones will be accounted for in the same manner
 as royalties and recorded as revenue upon achievement of the
 milestone, assuming all other revenue recognition criteria are
 met.&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 12pt; TEXT-INDENT: 4%"&gt;
 During the three months ended March&amp;#xA0;31, 2014, the Company
 recognized $6,250 of revenue associated with its collaboration with
 Celgene related to the recognition of discovery, research and
 development services. As of March&amp;#xA0;31, 2014, there was $48,958
 of deferred revenue related to the Company&amp;#x2019;s collaboration
 with Celgene which is classified as current or non-current in the
 accompanying balance sheets based on the contractual term of the
 arrangement.&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 18pt"&gt;
 &lt;b&gt;&lt;i&gt;Association Fran&amp;#xE7;aise contre les Myopathies&lt;/i&gt;&lt;/b&gt;&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 6pt; TEXT-INDENT: 4%"&gt;
 In January 2011, the Company entered into a research funding
 agreement with the Association Fran&amp;#xE7;aise contre les Myopathies
 (&amp;#x201C;AFM&amp;#x201D;), a nonprofit organization dedicated to curing
 rare neuromuscular diseases and providing treatments to reduce the
 associated disabilities of such diseases. As part of the agreement,
 AFM funded the Company 1,000 Euros to be used to advance the
 Company&amp;#x2019;s research, process development, manufacturing,
 preclinical development, and clinical development in gene therapy
 for beta-hemoglobinopathies in &amp;#xDF;-thalassemia and/or in Sickle
 Cell Disease.&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0px; FONT-SIZE: 1px; MARGIN-TOP: 12px"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 0pt; TEXT-INDENT: 4%"&gt;
 The funding, or a portion thereof depending on timing, shall be
 repaid to AFM upon any of the following events: (i)&amp;#xA0;upon
 out-licensing or sale of the program, (ii)&amp;#xA0;upon obtaining the
 first product authorization for the market, or (iii)&amp;#xA0;upon sale
 of the Company, provided that development of the program is active
 at the time of such sale. The agreement is for a period of four
 years. The Company believes that repayment of the funds paid under
 the agreement is not probable as of the date of the agreement,
 March&amp;#xA0;31, 2014 or December&amp;#xA0;31, 2013. The Company
 recognizes the revenue under this arrangement on a straight-line
 basis over the term of the agreement and will reassess the
 probability of repayment at the end of each reporting period.&lt;/p&gt;
 
 
 &lt;/div&gt;</us-gaap:CollaborativeArrangementDisclosureTextBlock>
  <us-gaap:ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock contextRef="eol_PE639928--1410-Q0002_STD_90_20140331_0" id="id_4932441_5F56EE34-E1B4-433E-BE1F-2A1433F6506F_1_0">&lt;div&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 6pt; TEXT-INDENT: 4%"&gt;
 The following table summarizes the stock option activity under the
 Company&amp;#x2019;s equity award plans:&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 12pt; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;table style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; BORDER-COLLAPSE: collapse" cellspacing="0" cellpadding="0" width="76%" align="center" border="0"&gt;
 &lt;tr&gt;
 &lt;td width="81%"&gt;&lt;/td&gt;
 &lt;td valign="bottom" width="5%"&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td valign="bottom" width="5%"&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 8pt; FONT-FAMILY: Times New Roman"&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;&lt;b&gt;Shares&lt;/b&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;&lt;b&gt;Weighted-&lt;br /&gt;
 average&lt;br /&gt;
 exercise&lt;br /&gt;
 price&lt;/b&gt;&lt;br /&gt;
 &lt;b&gt;per share&lt;/b&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; TEXT-INDENT: -1em"&gt;
 Outstanding at December&amp;#xA0;31, 2013&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;3,958&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;5.21&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 3em; TEXT-INDENT: -1em"&gt;
 Granted&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;724&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;23.87&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 3em; TEXT-INDENT: -1em"&gt;
 Exercised&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;(322&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;)&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;2.22&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 3em; TEXT-INDENT: -1em"&gt;
 Canceled or forfeited&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;(37&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;)&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;5.21&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 1px"&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 1px solid"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 1px solid"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; TEXT-INDENT: -1em"&gt;
 Outstanding at March&amp;#xA0;31, 2014&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;font style="FONT-SIZE: 8pt"&gt;&amp;#xA0;&amp;#xA0;&lt;/font&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;4,323&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;font style="FONT-SIZE: 8pt"&gt;&amp;#xA0;&lt;/font&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;8.56&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 1px"&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; TEXT-INDENT: -1em"&gt;
 Exercisable at March&amp;#xA0;31, 2014&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;font style="FONT-SIZE: 8pt"&gt;&amp;#xA0;&amp;#xA0;&lt;/font&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;1,442&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;font style="FONT-SIZE: 8pt"&gt;&amp;#xA0;&lt;/font&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;2.86&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 1px"&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; TEXT-INDENT: -1em"&gt;
 Vested and expected to vest at March&amp;#xA0;31, 2014&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;font style="FONT-SIZE: 8pt"&gt;&amp;#xA0;&amp;#xA0;&lt;/font&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;4,240&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;font style="FONT-SIZE: 8pt"&gt;&amp;#xA0;&lt;/font&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;8.50&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 1px"&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;/table&gt;
 &lt;/div&gt;</us-gaap:ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock>
  <us-gaap:NatureOfOperations contextRef="eol_PE639928--1410-Q0002_STD_90_20140331_0" id="id_4932441_146CEABC-2115-4B29-A32C-8658A5E4FD28_1_0">&lt;div&gt;
 &lt;table style="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" border="0" cellpadding="0" cellspacing="0" width="100%"&gt;
 &lt;tr&gt;
 &lt;td width="4%" valign="top" align="left"&gt;&lt;b&gt;1.&lt;/b&gt;&lt;/td&gt;
 &lt;td align="left" valign="top"&gt;&lt;b&gt;Description of the
 business&lt;/b&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;/table&gt;
 &lt;p style="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman"&gt;
 bluebird bio, Inc. (the &amp;#x201C;Company&amp;#x201D;) was incorporated in
 Delaware on April&amp;#xA0;16, 1992, and is headquartered in Cambridge,
 Massachusetts. The Company was formed to develop, manufacture and
 market therapies to safely and effectively deliver genes useful in
 the treatment of serious human diseases. Since its inception, the
 Company has devoted substantially all of its resources to its
 development efforts relating to its product candidates, including
 activities to manufacture product in compliance with good
 manufacturing practices (&amp;#x201C;GMP&amp;#x201D;), conduct clinical
 studies of its product candidates, provide general and
 administrative support for these operations and protect its
 intellectual property.&lt;/p&gt;
 &lt;/div&gt;</us-gaap:NatureOfOperations>
  <us-gaap:ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock contextRef="eol_PE639928--1410-Q0002_STD_90_20140331_0" id="id_4932441_33F0A3E3-130A-4346-9D44-1F0BE9A49C83_1_0">&lt;div&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 6pt; TEXT-INDENT: 4%"&gt;
 The following common stock equivalents were excluded from the
 calculation of diluted net loss per share for the periods indicated
 because including them would have had an anti-dilutive effect:&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 12pt; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;table style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; BORDER-COLLAPSE: collapse" cellspacing="0" cellpadding="0" width="76%" align="center" border="0"&gt;
 &lt;tr&gt;
 &lt;td width="77%"&gt;&lt;/td&gt;
 &lt;td valign="bottom" width="6%"&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td valign="bottom" width="6%"&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 8pt; FONT-FAMILY: Times New Roman"&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="6" align="center"&gt;
 &lt;b&gt;Three&amp;#xA0;months&amp;#xA0;ended&amp;#xA0;March&amp;#xA0;31,&lt;/b&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 8pt; FONT-FAMILY: Times New Roman"&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;&lt;b&gt;2014&lt;/b&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;&lt;b&gt;2013&lt;/b&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; TEXT-INDENT: -1em"&gt;
 Preferred stock&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap" align="right"&gt;
 &amp;#x2014;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;16,389&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; TEXT-INDENT: -1em"&gt;
 Warrants&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;338&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;440&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; TEXT-INDENT: -1em"&gt;
 Outstanding stock options&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;4,323&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;3,653&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; TEXT-INDENT: -1em"&gt;
 Unvested restricted stock&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;48&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;132&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 1px"&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 1px solid"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 1px solid"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 1px solid"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 1px solid"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;font style="FONT-SIZE: 8pt"&gt;&amp;#xA0;&amp;#xA0;&lt;/font&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;4,709&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;font style="FONT-SIZE: 8pt"&gt;&amp;#xA0;&amp;#xA0;&lt;/font&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;20,614&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 1px"&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 1px solid"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 1px solid"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 1px solid"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 1px solid"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;/table&gt;
 &lt;/div&gt;</us-gaap:ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock>
  <us-gaap:OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureAndSignificantAccountingPoliciesTextBlock contextRef="eol_PE639928--1410-Q0002_STD_90_20140331_0" id="id_4932441_D1400BD4-3A59-487B-A5B8-4A4552E5499B_1_0">&lt;div&gt;
 &lt;table style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; BORDER-COLLAPSE: collapse" cellspacing="0" cellpadding="0" width="100%" border="0"&gt;
 &lt;tr&gt;
 &lt;td valign="top" width="4%" align="left"&gt;&lt;b&gt;2.&lt;/b&gt;&lt;/td&gt;
 &lt;td valign="top" align="left"&gt;&lt;b&gt;Summary of significant accounting
 policies and basis of presentation&lt;/b&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;/table&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 6pt"&gt;
 &lt;b&gt;&lt;i&gt;Basis of presentation and principles of
 consolidation&lt;/i&gt;&lt;/b&gt;&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 6pt; TEXT-INDENT: 4%"&gt;
 The accompanying condensed consolidated financial statements are
 unaudited and have been prepared by the Company in accordance with
 accounting principles generally accepted in the United States
 (&amp;#x201C;GAAP&amp;#x201D;) as found in the Accounting Standards
 Codification (&amp;#x201C;ASC&amp;#x201D;) and Accounting Standards Update
 (&amp;#x201C;ASU&amp;#x201D;) of the Financial Accounting Standards Board
 (&amp;#x201C;FASB&amp;#x201D;). Certain information and footnote disclosures
 normally included in the Company&amp;#x2019;s annual financial
 statements have been condensed or omitted. These interim condensed
 consolidated financial statements, in the opinion of management,
 reflect all normal recurring adjustments necessary for a fair
 presentation of the Company&amp;#x2019;s financial position and results
 of operations for the interim periods ended March&amp;#xA0;31, 2014 and
 2013.&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 12pt; TEXT-INDENT: 4%"&gt;
 The results of operations for the interim periods are not
 necessarily indicative of the results of operations to be expected
 for the full year. These interim financial statements should be
 read in conjunction with the audited financial statements as of and
 for the year ended December&amp;#xA0;31, 2013, and the notes thereto,
 which are included in the Company&amp;#x2019;s Annual Report on Form
 10-K filed with the Securities and Exchange Commission (the
 &amp;#x201C;SEC&amp;#x201D;) on March&amp;#xA0;5, 2014.&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 12pt; TEXT-INDENT: 4%"&gt;
 The accompanying condensed consolidated financial statements
 include the accounts of the Company and its wholly-owned
 subsidiaries, bluebird bio France, SARL, bluebird bio Australia Pty
 Ltd. and bluebird bio Securities Corporation. All intercompany
 balances and transactions have been eliminated in consolidation.
 Any reference in these notes to applicable guidance is meant to
 refer to GAAP. The Company views its operations and manages its
 business in one operating segment. All material long-lived assets
 of the Company reside in the United States.&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 18pt"&gt;
 &lt;b&gt;&lt;i&gt;Summary of accounting policies&lt;/i&gt;&lt;/b&gt;&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 6pt; TEXT-INDENT: 4%"&gt;
 The significant accounting policies described in the
 Company&amp;#x2019;s audited financial statements as of and for the year
 ended December&amp;#xA0;31, 2013, and the notes thereto, which are
 included in the Annual Report on Form 10-K, have had no material
 changes during the three months ended March&amp;#xA0;31, 2014.&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 18pt"&gt;
 &lt;b&gt;&lt;i&gt;Use of estimates&lt;/i&gt;&lt;/b&gt;&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 6pt; TEXT-INDENT: 4%"&gt;
 The preparation of financial statements in conformity with GAAP
 requires management to make estimates and assumptions that affect
 the reported amounts in the financial statements and accompanying
 notes. Actual results could materially differ from those estimates.
 Management considers many factors in selecting appropriate
 financial accounting policies and controls, and in developing the
 estimates and assumptions that are used in the preparation of these
 financial statements. Management must apply significant judgment in
 this process. In addition, other factors may affect estimates,
 including: expected business and operational changes, sensitivity
 and volatility associated with the assumptions used in developing
 estimates, and whether historical trends are expected to be
 representative of future trends. The estimation process often may
 yield a range of potentially reasonable estimates of the ultimate
 future outcomes and management must select an amount that falls
 within that range of reasonable estimates. This process may result
 in actual results differing materially from those estimated amounts
 used in the preparation of the financial statements. Estimates are
 used in the following areas, among others: stock-based compensation
 expense, accrued expenses, revenue and income taxes.&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 18pt"&gt;
 &lt;b&gt;&lt;i&gt;Fair value of financial instruments&lt;/i&gt;&lt;/b&gt;&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 6pt; TEXT-INDENT: 4%"&gt;
 The Company is required to disclose information on all assets and
 liabilities reported at fair value that enables an assessment of
 the inputs used in determining the reported fair values. ASC 820,
 &lt;i&gt;Fair Value Measurements and Disclosures&lt;/i&gt;, establishes a
 hierarchy of inputs used in measuring fair value that maximizes the
 use of observable inputs and minimizes the use of unobservable
 inputs by requiring that the observable inputs be used when
 available. Observable inputs are inputs that market participants
 would use in pricing the asset or liability based on market data
 obtained from sources independent of the Company. Unobservable
 inputs are inputs that reflect the Company&amp;#x2019;s assumptions
 about the inputs that market participants would use in pricing the
 asset or liability, and are developed based on the best information
 available in the circumstances. The fair value hierarchy applies
 only to the valuation inputs used in determining the reported fair
 value of the investments and is not a measure of the investment
 credit quality. The three levels of the fair value hierarchy are
 described below:&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 4%; MARGIN-TOP: 6pt"&gt;
 Level 1&amp;#x2014;Valuations based on unadjusted quoted prices&amp;#xA0;in
 active markets for identical assets or liabilities that the Company
 has the ability to access at the measurement date.&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 4%; MARGIN-TOP: 6pt"&gt;
 Level 2&amp;#x2014;Valuations based on quoted prices for similar assets
 or liabilities in markets that are not active or for which all
 significant inputs are observable, either directly or
 indirectly.&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 4%; MARGIN-TOP: 6pt"&gt;
 Level 3&amp;#x2014;Valuations that require inputs that reflect the
 Company&amp;#x2019;s own assumptions that are both significant to the
 fair value measurement and unobservable. To the extent that
 valuation is based on models or inputs that are less observable or
 unobservable in the market, the determination of fair value
 requires more judgment. Accordingly, the degree of judgment
 exercised by the Company in determining fair value is greatest for
 instruments categorized in Level&amp;#xA0;3. A financial
 instrument&amp;#x2019;s level within the fair value hierarchy is based
 on the lowest level of any input that is significant to the fair
 value measurement.&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 12pt; TEXT-INDENT: 4%"&gt;
 The carrying amounts of accounts payable and accrued expenses
 approximate their fair values due to their short-term
 maturities.&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 18pt"&gt;
 &lt;b&gt;&lt;i&gt;Other Income and Expense&lt;/i&gt;&lt;/b&gt;&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 6pt; TEXT-INDENT: 4%"&gt;
 In March 2014, the Company received an award of $306 of tax
 incentives from the Massachusetts Life Sciences Center, which will
 allow the Company to monetize approximately $276 of state and
 research and development tax credits. In exchange for these
 incentives, the Company pledged to hire an incremental fifteen
 employees and to maintain the additional headcount through at least
 December&amp;#xA0;31, 2018. Failure to do so could result in the
 Company being required to repay some or all of these incentives.
 The Company has deferred and will amortize the benefit of this
 monetization on a straight-line basis over the five-year
 performance period, commencing when the pledge is achieved, which
 had not occurred as of March&amp;#xA0;31, 2014.&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 18pt"&gt;
 &lt;b&gt;&lt;i&gt;Net Income (Loss) Per Share&lt;/i&gt;&lt;/b&gt;&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 6pt; TEXT-INDENT: 4%"&gt;
 Basic net income (loss) per share is calculated by dividing net
 income (loss) attributable to common stockholders by the weighted
 average number of common shares outstanding during the period.
 Diluted net income per share is calculated by dividing the net
 income attributable to common stockholders by the weighted-average
 number of common equivalent shares outstanding for the period,
 including any dilutive effect from outstanding stock options,
 unvested restricted stock, and warrants using the treasury stock
 method.&lt;/p&gt;
 &lt;/div&gt;</us-gaap:OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureAndSignificantAccountingPoliciesTextBlock>
  <us-gaap:ScheduleOfNonvestedRestrictedStockUnitsActivityTableTextBlock contextRef="eol_PE639928--1410-Q0002_STD_90_20140331_0" id="id_4932441_DE746FCB-3807-4BDA-BE95-1F3D10E82AF0_1_0">&lt;div&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 0pt"&gt;
 &lt;b&gt;&lt;i&gt;Restricted common stock&lt;/i&gt;&lt;/b&gt;&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 12pt; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;table style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; BORDER-COLLAPSE: collapse" cellspacing="0" cellpadding="0" width="76%" align="center" border="0"&gt;
 &lt;tr&gt;
 &lt;td width="74%"&gt;&lt;/td&gt;
 &lt;td valign="bottom" width="10%"&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td valign="bottom" width="10%"&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 8pt; FONT-FAMILY: Times New Roman"&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;&lt;b&gt;Shares&lt;/b&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;&lt;b&gt;&lt;font style="WHITE-SPACE: nowrap"&gt;Weighted-average&lt;/font&gt;&lt;br /&gt;
 grant date&lt;/b&gt;&lt;br /&gt;
 &lt;b&gt;fair value&lt;/b&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; TEXT-INDENT: -1em"&gt;
 Unvested balance at December&amp;#xA0;31, 2013&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;69&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;0.95&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 3em; TEXT-INDENT: -1em"&gt;
 Granted&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap" align="right"&gt;
 &amp;#x2014;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap" align="right"&gt;
 &amp;#x2014;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 3em; TEXT-INDENT: -1em"&gt;
 Vested&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;(21&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;)&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;0.95&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 3em; TEXT-INDENT: -1em"&gt;
 Forfeited&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap" align="right"&gt;
 &amp;#x2014;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap" align="right"&gt;
 &amp;#x2014;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 1px"&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 1px solid"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 1px solid"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 1px solid"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 1px solid"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; TEXT-INDENT: -1em"&gt;
 Unvested balance at March 31, 2014&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;font style="FONT-SIZE: 8pt"&gt;&amp;#xA0;&amp;#xA0;&lt;/font&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;48&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;font style="FONT-SIZE: 8pt"&gt;&amp;#xA0;&lt;/font&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;0.95&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 1px"&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;/table&gt;
 &lt;/div&gt;</us-gaap:ScheduleOfNonvestedRestrictedStockUnitsActivityTableTextBlock>
  <us-gaap:WeightedAverageNumberOfShareOutstandingBasicAndDiluted contextRef="eol_PE639928--1410-Q0002_STD_90_20140331_0" unitRef="shares" decimals="-3" id="id_4932441_413C4E54-82DB-4CA6-B62D-A5D6B3539290_1_12">24148000</us-gaap:WeightedAverageNumberOfShareOutstandingBasicAndDiluted>
  <us-gaap:ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice contextRef="eol_PE639928--1410-Q0002_STD_90_20140331_0" unitRef="iso4217_USD_per_shares" decimals="2" id="id_4932441_7ED66B1A-72DB-4354-AF57-3968D08F95EA_5001_3">23.87</us-gaap:ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice>
  <us-gaap:NetCashProvidedByUsedInOperatingActivitiesContinuingOperations contextRef="eol_PE639928--1410-Q0002_STD_90_20140331_0" unitRef="iso4217_USD" decimals="-3" id="id_4932441_20A79337-FA92-425D-A003-B57129FE959B_1_14">-11934000</us-gaap:NetCashProvidedByUsedInOperatingActivitiesContinuingOperations>
  <us-gaap:CashAndCashEquivalentsDisclosureTextBlock contextRef="eol_PE639928--1410-Q0002_STD_90_20140331_0" id="id_4932441_47383D80-DE3F-4252-87B3-D0832EC4AE9B_1_0">&lt;div&gt;
 &lt;table style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; BORDER-COLLAPSE: collapse" cellspacing="0" cellpadding="0" width="100%" border="0"&gt;
 &lt;tr&gt;
 &lt;td valign="top" width="4%" align="left"&gt;&lt;b&gt;3.&lt;/b&gt;&lt;/td&gt;
 &lt;td valign="top" align="left"&gt;&lt;b&gt;Cash and cash equivalents&lt;/b&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;/table&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 6pt; TEXT-INDENT: 4%"&gt;
 The Company considers all highly liquid securities with original
 final maturities of three months or less from the date of purchase
 to be cash equivalents. As of March&amp;#xA0;31, 2014 and
 December&amp;#xA0;31, 2013, cash and cash equivalents comprise funds in
 cash and money market accounts. The following table presents the
 cash and cash equivalents carried at fair value:&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 12pt; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;table style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; BORDER-COLLAPSE: collapse" cellspacing="0" cellpadding="0" width="92%" align="center" border="0"&gt;
 &lt;tr&gt;
 &lt;td width="50%"&gt;&lt;/td&gt;
 &lt;td valign="bottom" width="8%"&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td valign="bottom" width="8%"&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td valign="bottom" width="8%"&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td valign="bottom" width="8%"&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 8pt; FONT-FAMILY: Times New Roman"&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;
 &lt;p style="FONT-SIZE: 8pt; FONT-FAMILY: Times New Roman; BORDER-BOTTOM: #000000 1pt solid; WIDTH: 39.5pt"&gt;
 &lt;b&gt;Description&lt;/b&gt;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;&lt;b&gt;Total&lt;/b&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;&lt;b&gt;Quoted&amp;#xA0;prices&amp;#xA0;in&lt;br /&gt;
 active markets&lt;br /&gt;
 (Level 1)&lt;/b&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;&lt;b&gt;Significant&amp;#xA0;other&lt;br /&gt;
 observable&amp;#xA0;inputs&lt;br /&gt;
 (Level 2)&lt;/b&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;&lt;b&gt;Significant&lt;br /&gt;
 unobservable&amp;#xA0;inputs&lt;br /&gt;
 (Level 3)&lt;/b&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; TEXT-INDENT: -1em"&gt;
 &lt;b&gt;March&amp;#xA0;31, 2014&lt;/b&gt;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 3em; TEXT-INDENT: -1em"&gt;
 Total cash and cash equivalents&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;192,499&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;192,499&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap" align="right"&gt;
 &amp;#x2014;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap" align="right"&gt;
 &amp;#x2014;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 1px"&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; TEXT-INDENT: -1em"&gt;
 &lt;b&gt;December 31, 2013&lt;/b&gt;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;font style="FONT-SIZE: 8pt"&gt;&amp;#xA0;&amp;#xA0;&lt;/font&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;font style="FONT-SIZE: 8pt"&gt;&amp;#xA0;&amp;#xA0;&lt;/font&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;font style="FONT-SIZE: 8pt"&gt;&amp;#xA0;&amp;#xA0;&lt;/font&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;font style="FONT-SIZE: 8pt"&gt;&amp;#xA0;&amp;#xA0;&lt;/font&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 3em; TEXT-INDENT: -1em"&gt;
 Total cash and cash equivalents&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;font style="FONT-SIZE: 8pt"&gt;&amp;#xA0;&amp;#xA0;&lt;/font&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;206,279&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;font style="FONT-SIZE: 8pt"&gt;&amp;#xA0;&amp;#xA0;&lt;/font&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;206,279&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;font style="FONT-SIZE: 8pt"&gt;&amp;#xA0;&amp;#xA0;&lt;/font&gt;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap" align="right"&gt;
 &amp;#x2014;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;font style="FONT-SIZE: 8pt"&gt;&amp;#xA0;&amp;#xA0;&lt;/font&gt;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap" align="right"&gt;
 &amp;#x2014;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 1px"&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;/table&gt;
 &lt;/div&gt;</us-gaap:CashAndCashEquivalentsDisclosureTextBlock>
  <us-gaap:ScheduleOfCompensationCostForShareBasedPaymentArrangementsAllocationOfShareBasedCompensationCostsByPlanTableTextBlock contextRef="eol_PE639928--1410-Q0002_STD_90_20140331_0" id="id_4932441_29076303-C718-4A6D-9E95-8A53FFF66AF0_1_0">&lt;div&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 6pt; TEXT-INDENT: 4%"&gt;
 Stock-based compensation expense by award type was as follows:&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 12pt; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;table style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; BORDER-COLLAPSE: collapse" cellspacing="0" cellpadding="0" width="76%" align="center" border="0"&gt;
 &lt;tr&gt;
 &lt;td width="76%"&gt;&lt;/td&gt;
 &lt;td valign="bottom" width="8%"&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td valign="bottom" width="8%"&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 8pt; FONT-FAMILY: Times New Roman"&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="6" align="center"&gt;
 &lt;b&gt;Three&amp;#xA0;months&amp;#xA0;ended&amp;#xA0;March&amp;#xA0;31,&lt;/b&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 8pt; FONT-FAMILY: Times New Roman"&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;&lt;b&gt;2014&lt;/b&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;&lt;b&gt;2013&lt;/b&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; TEXT-INDENT: -1em"&gt;
 Stock options&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;2,477&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;639&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; TEXT-INDENT: -1em"&gt;
 Restricted stock awards&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;16&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;22&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 1px"&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 1px solid"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 1px solid"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 1px solid"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 1px solid"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;font style="FONT-SIZE: 8pt"&gt;&amp;#xA0;&amp;#xA0;&lt;/font&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;2,493&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;font style="FONT-SIZE: 8pt"&gt;&amp;#xA0;&amp;#xA0;&lt;/font&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;661&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 1px"&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;/table&gt;
 &lt;/div&gt;</us-gaap:ScheduleOfCompensationCostForShareBasedPaymentArrangementsAllocationOfShareBasedCompensationCostsByPlanTableTextBlock>
  <us-gaap:EarningsPerShareBasicAndDiluted contextRef="eol_PE639928--1410-Q0002_STD_90_20140331_0" unitRef="iso4217_USD_per_shares" decimals="2" id="id_4932441_413C4E54-82DB-4CA6-B62D-A5D6B3539290_1_11">-0.44</us-gaap:EarningsPerShareBasicAndDiluted>
  <us-gaap:ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice contextRef="eol_PE639928--1410-Q0002_STD_90_20140331_0" unitRef="iso4217_USD_per_shares" decimals="2" id="id_4932441_7ED66B1A-72DB-4354-AF57-3968D08F95EA_5001_4">2.22</us-gaap:ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice>
  <us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross contextRef="eol_PE639928--1410-Q0002_STD_90_20140331_0" unitRef="shares" decimals="-3" id="id_4932441_8E531719-BFC7-480A-8BD4-FBFA37529018_5001_3">724000</us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross>
  <us-gaap:SubsequentEventsTextBlock contextRef="eol_PE639928--1410-Q0002_STD_90_20140331_0" id="id_4932441_2A314AE0-05F8-44BB-B80D-FF0FDE0AE435_1_0">&lt;div&gt;
 &lt;table style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; BORDER-COLLAPSE: collapse" cellspacing="0" cellpadding="0" width="100%" border="0"&gt;
 &lt;tr&gt;
 &lt;td valign="top" width="4%" align="left"&gt;&lt;b&gt;9.&lt;/b&gt;&lt;/td&gt;
 &lt;td valign="top" align="left"&gt;&lt;b&gt;Subsequent events&lt;/b&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;/table&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 6pt; TEXT-INDENT: 4%"&gt;
 The Company has evaluated all events or transactions that occurred
 after March&amp;#xA0;31, 2014. In the judgment of management, there
 were no material events that impacted the unaudited condensed
 consolidated financial statements or disclosures.&lt;/p&gt;
 &lt;/div&gt;</us-gaap:SubsequentEventsTextBlock>
  <us-gaap:EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1 contextRef="eol_PE639928--1410-Q0002_STD_90_20140331_0" id="id_4932441_B3534322-9E6D-4BEE-A5A4-AA330213B16A_1_1">P3Y2M12D</us-gaap:EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1>
  <us-gaap:IncomeTaxDisclosureTextBlock contextRef="eol_PE639928--1410-Q0002_STD_90_20140331_0" id="id_4932441_25AF8802-B10D-47AA-96F6-62613D1C6835_1_0">&lt;div&gt;
 &lt;table style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; BORDER-COLLAPSE: collapse" cellspacing="0" cellpadding="0" width="100%" border="0"&gt;
 &lt;tr&gt;
 &lt;td valign="top" width="4%" align="left"&gt;&lt;b&gt;7.&lt;/b&gt;&lt;/td&gt;
 &lt;td valign="top" align="left"&gt;&lt;b&gt;Income taxes&lt;/b&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;/table&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 6pt; TEXT-INDENT: 4%"&gt;
 Deferred tax assets and deferred tax liabilities are recognized
 based on temporary differences between the financial reporting and
 tax basis of assets and liabilities using statutory rates. A
 valuation allowance is recorded against deferred tax assets if it
 is more likely than not that some or all of the deferred tax assets
 will not be realized. There were no significant income tax
 provisions or benefits for the three months ended March&amp;#xA0;31,
 2014 and 2013. Due to the uncertainty surrounding the realization
 of the favorable tax attributes in future tax returns, the Company
 has recorded a full valuation allowance against the Company&amp;#x2019;s
 otherwise recognizable net deferred tax assets. The Company has
 allocated its valuation allowance in accordance with the provisions
 of ASC 740, &lt;i&gt;Income Taxes&lt;/i&gt;, which resulted in a current
 deferred tax asset of $693 and a non-current deferred tax liability
 of $693.&lt;/p&gt;
 &lt;/div&gt;</us-gaap:IncomeTaxDisclosureTextBlock>
  <us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriod contextRef="eol_PE639928--1410-Q0002_STD_90_20140331_0" unitRef="shares" decimals="-3" id="id_4932441_8E531719-BFC7-480A-8BD4-FBFA37529018_5001_5">37000</us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriod>
  <us-gaap:BasisOfAccountingPolicyPolicyTextBlock contextRef="eol_PE639928--1410-Q0002_STD_90_20140331_0" id="id_4932441_860084CD-9500-41B3-B6D3-21934327D0EE_1_0">&lt;div&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 18pt"&gt;
 &lt;b&gt;&lt;i&gt;Summary of accounting policies&lt;/i&gt;&lt;/b&gt;&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 6pt; TEXT-INDENT: 4%"&gt;
 The significant accounting policies described in the
 Company&amp;#x2019;s audited financial statements as of and for the year
 ended December&amp;#xA0;31, 2013, and the notes thereto, which are
 included in the Annual Report on Form 10-K, have had no material
 changes during the three months ended March&amp;#xA0;31, 2014.&lt;/p&gt;
 &lt;/div&gt;</us-gaap:BasisOfAccountingPolicyPolicyTextBlock>
  <us-gaap:EarningsPerShareTextBlock contextRef="eol_PE639928--1410-Q0002_STD_90_20140331_0" id="id_4932441_D31F7C83-8972-4B32-A207-FC146614B32A_1_0">&lt;div&gt;
 &lt;table style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; BORDER-COLLAPSE: collapse" cellspacing="0" cellpadding="0" width="100%" border="0"&gt;
 &lt;tr&gt;
 &lt;td valign="top" width="4%" align="left"&gt;&lt;b&gt;8.&lt;/b&gt;&lt;/td&gt;
 &lt;td valign="top" align="left"&gt;&lt;b&gt;Net loss per share&lt;/b&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;/table&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 6pt; TEXT-INDENT: 4%"&gt;
 The following common stock equivalents were excluded from the
 calculation of diluted net loss per share for the periods indicated
 because including them would have had an anti-dilutive effect:&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 12pt; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;table style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; BORDER-COLLAPSE: collapse" cellspacing="0" cellpadding="0" width="76%" align="center" border="0"&gt;
 &lt;tr&gt;
 &lt;td width="77%"&gt;&lt;/td&gt;
 &lt;td valign="bottom" width="6%"&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td valign="bottom" width="6%"&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 8pt; FONT-FAMILY: Times New Roman"&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="6" align="center"&gt;
 &lt;b&gt;Three&amp;#xA0;months&amp;#xA0;ended&amp;#xA0;March&amp;#xA0;31,&lt;/b&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 8pt; FONT-FAMILY: Times New Roman"&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;&lt;b&gt;2014&lt;/b&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;&lt;b&gt;2013&lt;/b&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; TEXT-INDENT: -1em"&gt;
 Preferred stock&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap" align="right"&gt;
 &amp;#x2014;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;16,389&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; TEXT-INDENT: -1em"&gt;
 Warrants&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;338&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;440&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; TEXT-INDENT: -1em"&gt;
 Outstanding stock options&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;4,323&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;3,653&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; TEXT-INDENT: -1em"&gt;
 Unvested restricted stock&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;48&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;132&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 1px"&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 1px solid"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 1px solid"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 1px solid"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 1px solid"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;font style="FONT-SIZE: 8pt"&gt;&amp;#xA0;&amp;#xA0;&lt;/font&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;4,709&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;font style="FONT-SIZE: 8pt"&gt;&amp;#xA0;&amp;#xA0;&lt;/font&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;20,614&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 1px"&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 1px solid"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 1px solid"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 1px solid"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 1px solid"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;/table&gt;
 &lt;/div&gt;</us-gaap:EarningsPerShareTextBlock>
  <us-gaap:StockIssuedDuringPeriodSharesStockOptionsExercised contextRef="eol_PE639928--1410-Q0002_STD_90_20140331_0" unitRef="shares" decimals="-3" id="id_4932441_8E531719-BFC7-480A-8BD4-FBFA37529018_5001_4">322000</us-gaap:StockIssuedDuringPeriodSharesStockOptionsExercised>
  <us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice contextRef="eol_PE639928--1410-Q0002_STD_90_20140331_0" unitRef="iso4217_USD_per_shares" decimals="2" id="id_4932441_7ED66B1A-72DB-4354-AF57-3968D08F95EA_5001_5">5.21</us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice>
  <us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount contextRef="eol_PE639928--1410-Q0002_STD_90_20140331_0" unitRef="shares" decimals="-3" id="id_4932441_B9203DCB-B139-4617-A4D3-186272844528_1_4">4709000</us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount>
  <us-gaap:UseOfEstimates contextRef="eol_PE639928--1410-Q0002_STD_90_20140331_0" id="id_4932441_A2975944-B973-465A-AEFE-79AC130BD01B_1_0">&lt;div&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 18pt"&gt;
 &lt;b&gt;&lt;i&gt;Use of estimates&lt;/i&gt;&lt;/b&gt;&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 6pt; TEXT-INDENT: 4%"&gt;
 The preparation of financial statements in conformity with GAAP
 requires management to make estimates and assumptions that affect
 the reported amounts in the financial statements and accompanying
 notes. Actual results could materially differ from those estimates.
 Management considers many factors in selecting appropriate
 financial accounting policies and controls, and in developing the
 estimates and assumptions that are used in the preparation of these
 financial statements. Management must apply significant judgment in
 this process. In addition, other factors may affect estimates,
 including: expected business and operational changes, sensitivity
 and volatility associated with the assumptions used in developing
 estimates, and whether historical trends are expected to be
 representative of future trends. The estimation process often may
 yield a range of potentially reasonable estimates of the ultimate
 future outcomes and management must select an amount that falls
 within that range of reasonable estimates. This process may result
 in actual results differing materially from those estimated amounts
 used in the preparation of the financial statements. Estimates are
 used in the following areas, among others: stock-based compensation
 expense, accrued expenses, revenue and income taxes.&lt;/p&gt;
 &lt;/div&gt;</us-gaap:UseOfEstimates>
  <us-gaap:EarningsPerSharePolicyTextBlock contextRef="eol_PE639928--1410-Q0002_STD_90_20140331_0" id="id_4932441_8EEF60D1-6590-4C6E-B9D3-A22DFF9C48DB_1_0">&lt;div&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 18pt"&gt;
 &lt;b&gt;&lt;i&gt;Net Income (Loss) Per Share&lt;/i&gt;&lt;/b&gt;&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 6pt; TEXT-INDENT: 4%"&gt;
 Basic net income (loss) per share is calculated by dividing net
 income (loss) attributable to common stockholders by the weighted
 average number of common shares outstanding during the period.
 Diluted net income per share is calculated by dividing the net
 income attributable to common stockholders by the weighted-average
 number of common equivalent shares outstanding for the period,
 including any dilutive effect from outstanding stock options,
 unvested restricted stock, and warrants using the treasury stock
 method.&lt;/p&gt;
 &lt;/div&gt;</us-gaap:EarningsPerSharePolicyTextBlock>
  <us-gaap:FairValueOfFinancialInstrumentsPolicy contextRef="eol_PE639928--1410-Q0002_STD_90_20140331_0" id="id_4932441_20E611A3-0F49-4CF2-BE04-325AC71E62A1_1_0">&lt;div&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 18pt"&gt;
 &lt;b&gt;&lt;i&gt;Fair value of financial instruments&lt;/i&gt;&lt;/b&gt;&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 6pt; TEXT-INDENT: 4%"&gt;
 The Company is required to disclose information on all assets and
 liabilities reported at fair value that enables an assessment of
 the inputs used in determining the reported fair values. ASC 820,
 &lt;i&gt;Fair Value Measurements and Disclosures&lt;/i&gt;, establishes a
 hierarchy of inputs used in measuring fair value that maximizes the
 use of observable inputs and minimizes the use of unobservable
 inputs by requiring that the observable inputs be used when
 available. Observable inputs are inputs that market participants
 would use in pricing the asset or liability based on market data
 obtained from sources independent of the Company. Unobservable
 inputs are inputs that reflect the Company&amp;#x2019;s assumptions
 about the inputs that market participants would use in pricing the
 asset or liability, and are developed based on the best information
 available in the circumstances. The fair value hierarchy applies
 only to the valuation inputs used in determining the reported fair
 value of the investments and is not a measure of the investment
 credit quality. The three levels of the fair value hierarchy are
 described below:&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 4%; MARGIN-TOP: 6pt"&gt;
 Level 1&amp;#x2014;Valuations based on unadjusted quoted prices&amp;#xA0;in
 active markets for identical assets or liabilities that the Company
 has the ability to access at the measurement date.&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 4%; MARGIN-TOP: 6pt"&gt;
 Level 2&amp;#x2014;Valuations based on quoted prices for similar assets
 or liabilities in markets that are not active or for which all
 significant inputs are observable, either directly or
 indirectly.&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 4%; MARGIN-TOP: 6pt"&gt;
 Level 3&amp;#x2014;Valuations that require inputs that reflect the
 Company&amp;#x2019;s own assumptions that are both significant to the
 fair value measurement and unobservable. To the extent that
 valuation is based on models or inputs that are less observable or
 unobservable in the market, the determination of fair value
 requires more judgment. Accordingly, the degree of judgment
 exercised by the Company in determining fair value is greatest for
 instruments categorized in Level&amp;#xA0;3. A financial
 instrument&amp;#x2019;s level within the fair value hierarchy is based
 on the lowest level of any input that is significant to the fair
 value measurement.&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 12pt; TEXT-INDENT: 4%"&gt;
 The carrying amounts of accounts payable and accrued expenses
 approximate their fair values due to their short-term
 maturities.&lt;/p&gt;
 &lt;/div&gt;</us-gaap:FairValueOfFinancialInstrumentsPolicy>
  <us-gaap:ScheduleOfCashAndCashEquivalentsTableTextBlock contextRef="eol_PE639928--1410-Q0002_STD_90_20140331_0" id="id_4932441_9096A5EA-3CE7-4595-A122-E82C968EA822_1_0">&lt;div&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 6pt; TEXT-INDENT: 4%"&gt;
 The following table presents the cash and cash equivalents carried
 at fair value:&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 12pt; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;table style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; BORDER-COLLAPSE: collapse" cellspacing="0" cellpadding="0" width="92%" align="center" border="0"&gt;
 &lt;tr&gt;
 &lt;td width="50%"&gt;&lt;/td&gt;
 &lt;td valign="bottom" width="8%"&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td valign="bottom" width="8%"&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td valign="bottom" width="8%"&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td valign="bottom" width="8%"&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 8pt; FONT-FAMILY: Times New Roman"&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;
 &lt;p style="FONT-SIZE: 8pt; FONT-FAMILY: Times New Roman; BORDER-BOTTOM: #000000 1pt solid; WIDTH: 39.5pt"&gt;
 &lt;b&gt;Description&lt;/b&gt;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;&lt;b&gt;Total&lt;/b&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;&lt;b&gt;Quoted&amp;#xA0;prices&amp;#xA0;in&lt;br /&gt;
 active markets&lt;br /&gt;
 (Level 1)&lt;/b&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;&lt;b&gt;Significant&amp;#xA0;other&lt;br /&gt;
 observable&amp;#xA0;inputs&lt;br /&gt;
 (Level 2)&lt;/b&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;&lt;b&gt;Significant&lt;br /&gt;
 unobservable&amp;#xA0;inputs&lt;br /&gt;
 (Level 3)&lt;/b&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; TEXT-INDENT: -1em"&gt;
 &lt;b&gt;March&amp;#xA0;31, 2014&lt;/b&gt;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 3em; TEXT-INDENT: -1em"&gt;
 Total cash and cash equivalents&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;192,499&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;192,499&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap" align="right"&gt;
 &amp;#x2014;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap" align="right"&gt;
 &amp;#x2014;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 1px"&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; TEXT-INDENT: -1em"&gt;
 &lt;b&gt;December 31, 2013&lt;/b&gt;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;font style="FONT-SIZE: 8pt"&gt;&amp;#xA0;&amp;#xA0;&lt;/font&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;font style="FONT-SIZE: 8pt"&gt;&amp;#xA0;&amp;#xA0;&lt;/font&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;font style="FONT-SIZE: 8pt"&gt;&amp;#xA0;&amp;#xA0;&lt;/font&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;font style="FONT-SIZE: 8pt"&gt;&amp;#xA0;&amp;#xA0;&lt;/font&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 3em; TEXT-INDENT: -1em"&gt;
 Total cash and cash equivalents&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;font style="FONT-SIZE: 8pt"&gt;&amp;#xA0;&amp;#xA0;&lt;/font&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;206,279&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;font style="FONT-SIZE: 8pt"&gt;&amp;#xA0;&amp;#xA0;&lt;/font&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;206,279&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;font style="FONT-SIZE: 8pt"&gt;&amp;#xA0;&amp;#xA0;&lt;/font&gt;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap" align="right"&gt;
 &amp;#x2014;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;font style="FONT-SIZE: 8pt"&gt;&amp;#xA0;&amp;#xA0;&lt;/font&gt;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap" align="right"&gt;
 &amp;#x2014;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 1px"&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="BORDER-TOP: #000000 3px double"&gt;&amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;/table&gt;
 &lt;/div&gt;</us-gaap:ScheduleOfCashAndCashEquivalentsTableTextBlock>
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 The accompanying condensed consolidated financial statements are
 unaudited and have been prepared by the Company in accordance with
 accounting principles generally accepted in the United States
 (&amp;#x201C;GAAP&amp;#x201D;) as found in the Accounting Standards
 Codification (&amp;#x201C;ASC&amp;#x201D;) and Accounting Standards Update
 (&amp;#x201C;ASU&amp;#x201D;) of the Financial Accounting Standards Board
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 normally included in the Company&amp;#x2019;s annual financial
 statements have been condensed or omitted. These interim condensed
 consolidated financial statements, in the opinion of management,
 reflect all normal recurring adjustments necessary for a fair
 presentation of the Company&amp;#x2019;s financial position and results
 of operations for the interim periods ended March&amp;#xA0;31, 2014 and
 2013.&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 12pt; TEXT-INDENT: 4%"&gt;
 The results of operations for the interim periods are not
 necessarily indicative of the results of operations to be expected
 for the full year. These interim financial statements should be
 read in conjunction with the audited financial statements as of and
 for the year ended December&amp;#xA0;31, 2013, and the notes thereto,
 which are included in the Company&amp;#x2019;s Annual Report on Form
 10-K filed with the Securities and Exchange Commission (the
 &amp;#x201C;SEC&amp;#x201D;) on March&amp;#xA0;5, 2014.&lt;/p&gt;
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 The accompanying condensed consolidated financial statements
 include the accounts of the Company and its wholly-owned
 subsidiaries, bluebird bio France, SARL, bluebird bio Australia Pty
 Ltd. and bluebird bio Securities Corporation. All intercompany
 balances and transactions have been eliminated in consolidation.
 Any reference in these notes to applicable guidance is meant to
 refer to GAAP. The Company views its operations and manages its
 business in one operating segment. All material long-lived assets
 of the Company reside in the United States.&lt;/p&gt;
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 incentives from the Massachusetts Life Sciences Center, which will
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 research and development tax credits. In exchange for these
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