Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 49,075	$ 63,617
Marketable securities	49,976	79,402
Accounts receivable	5,858	8,206
Receivable due from Roche	4,870	2,007
Inventory	10,349	10,438
Prepaid expenses and other current assets	5,338	5,251
Total current assets	125,466	168,921
Property and equipment, net	39,553	41,486
Restricted cash	1,395	1,395
Other assets	2,140	2,233
Total assets	168,554	214,035
Current liabilities:
Accounts payable	10,427	11,898
Accrued expenses and other current liabilities	19,240	20,578
Deferred revenue	1,985	2,104
Roche related-party deferred revenue	293	3,747
Current portion of deferred rent	2,418	2,324
Total current liabilities	34,363	40,651
Deferred rent, net of current portion and other non-current liabilities	7,874	8,538
Commitments and contingencies (Note 15)
Stockholders’ equity:
Common stock, $0.0001 par value, 150,000,000 shares authorized; 35,575,570 and 35,281,001 shares issued and outstanding at March 31, 2017 and December 31, 2016, respectively	4	4
Additional paid-in capital	517,698	509,664
Accumulated other comprehensive loss	(49)	(14)
Accumulated deficit	(391,336)	(344,808)
Total stockholders’ equity	126,317	164,846
Total liabilities and stockholders’ equity	$ 168,554	$ 214,035