Concentration of Business Risk

6 Months Ended

Jun. 30, 2013

Concentration of Business Risk

Concentration of Business Risk

6. Concentration of Business Risk

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 June 30,				Six Months Ended June 30,
	2013		2012		2013		2012
Partner A	20	%	90	%	40	%	84	%
Partner B	6	%	4	%	15	%	6	%
Partner C	40	%	0	%	22	%	0	%
Partner D	19	%	4	%	14	%	5	%

Contract receivables from four significant partners comprised approximately 89 percent of our contract receivables at June 30, 2013. Contract receivables from four significant partners comprised approximately 83 percent of our contract receivables at December 31, 2012.