Concentration of Business Risk (Tables)

3 Months Ended

Mar. 31, 2014

Concentration of Business Risk [Abstract]

Schedule of revenue from significant partners

We have historically funded our operations from collaborations with corporate partners and a relatively small number of partners have accounted for a significant percentage of our revenue. Revenue from significant partners, which is defined as ten percent or more of our total revenue, was as follows:

	Three Months Ended March 31,
	2014			2013
Partner A		36	%		9	%
Partner B		27	%		1	%
Partner C		12	%		23	%
Partner D		12	%		6	%
Partner E		0	%		58	%