Condensed Consolidated Balance Sheets (unaudited) - USD ($) $ in Thousands		Mar. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents		$ 153,790	$ 140,544
Short-term marketable securities		313,069	278,417
Accounts receivable		28,989	35,690
Inventory		10,256	9,136
Prepaid expenses and other current assets		6,151	5,204
Total current assets		512,255	468,991
Long-term marketable securities		25,916	77,563
Property and equipment, net		30,581	31,003
Capitalized license fees		7,557	7,800
Other assets		2,862	2,046
Total Assets	[1]	579,171	587,403
Current liabilities:
Accounts payable		7,163	10,642
Accrued compensation		14,683	12,986
Accrued expenses		9,137	7,081
Capital lease, current		96	97
Deferred revenue		17,113	16,138
Total current liabilities		48,192	46,944
Capital lease, net of current portion		100	119
Deferred rent, net of current portion		8,975	7,844
Obligation related to royalty		7,120	7,338
Other long-term liabilities		150	206
Total Liabilities	[1]	64,537	62,451
Commitments and contingencies (Note 7)
Redeemable noncontrolling interest		46,500	41,800
Stockholders’ equity:
Common stock, par value of $0.00001 per share; 350,000,000 shares authorized as of March 31, 2019 and December 31, 2018; 86,098,474 and 85,832,454 shares issued and outstanding as of March 31, 2019 and December 31, 2018, respectively		1	1
Additional paid-in capital		771,009	764,033
Accumulated other comprehensive loss		333	(83)
Accumulated deficit		(303,209)	(280,799)
Total Stockholders’ Equity		468,134	483,152
Total Liabilities, Redeemable Noncontrolling Interest and Stockholders’ Equity		$ 579,171	$ 587,403

[1] As of March 31, 2019 and December 31, 2018, includes $47.0 million and $48.3 million of assets, respectively, that can be used only to settle obligations of the consolidated variable interest entity (“VIE”) and VIE’s subsidiaries, and $942,000 and $1.2 million of liabilities of the consolidated VIE and VIE’s subsidiaries, respectively, for which their creditors do not have recourse to the general credit of the Company. See Note 3.