CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Current assets
Cash and cash equivalents	$ 263,237	$ 209,298
Marketable securities	129,651	157,742
Prepaid expenses and other current assets	10,406	1,330
Total current assets	403,294	368,370
Restricted cash	1,540
Property and equipment, net	11,321	2,256
Intangible assets, net	13,550
Goodwill	25,798
Other assets	9,226	127
Total assets	464,729	370,753
Current liabilities
Accounts payable	4,450	2,320
Deferred revenue	15,000
Accrued expenses and other current liabilities	7,550	4,405
Total current liabilities	27,000	6,725
Deferred revenue, less current portion	39,078
Contingent consideration	16,021
Other non-current liabilities	6,456	1,439
Total liabilities	$ 88,555	$ 8,164
COMMITMENTS AND CONTINGENCIES (NOTE 12)
STOCKHOLDERS' EQUITY
Preferred Stock, $0.001 par value, 10,000,000 and 0 shares authorized, issued and outstanding as of June 30, 2015 and December 31, 2014, respectively
Common stock, $0.001 par value, 200,000,000 shares authorized, 43,569,372 and 41,855,304 shares issued and outstanding, excluding 1,387,580 and 2,180,129 shares subject to repurchase at June 30, 2015 and December 31, 2014, respectively	$ 44	$ 42
Additional paid-in capital	469,773	420,848
Accumulated other comprehensive income (loss)	340	(297)
Accumulated deficit	(93,983)	(58,004)
Total stockholders' equity	376,174	362,589
Total liabilities and stockholders' equity	$ 464,729	$ 370,753