Consolidated Balance Sheets - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 63,617,000	$ 117,763,000
Marketable securities	79,402,000	89,607,000
Accounts receivable, net of allowance of $0 and $171 at December 31, 2016 and 2015, respectively	8,206,000	7,362,000
Receivable due from Roche	2,007,000	403,000
Inventory	10,438,000	7,992,000
Prepaid expenses and other current assets	5,251,000	6,517,000
Total current assets	168,921,000	229,644,000
Marketable securities		24,939,000
Property and equipment, net	41,486,000	41,333,000
Restricted cash	1,395,000	1,395,000
Other assets	2,233,000	678,000
Total assets	214,035,000	297,989,000
Current liabilities:
Accounts payable	11,898,000	10,469,000
Accrued expenses and other current liabilities	20,578,000	12,822,000
Deferred revenue	2,104,000	717,000
Roche related-party deferred revenue	3,747,000	3,742,000
Current portion of deferred rent	2,324,000	2,146,000
Total current liabilities	40,651,000	29,896,000
Deferred rent, net of current portion and other non-current liabilities	8,538,000	10,404,000
Commitments and contingencies (Note 12)
Stockholders’ equity:
Common stock, $0.0001 par value, 150,000,000 shares authorized; 35,281,001 and 34,513,845 shares issued and outstanding at December 31, 2016 and 2015, respectively	4,000	3,000
Additional paid-in capital	509,664,000	489,480,000
Accumulated other comprehensive loss	(14,000)	(178,000)
Accumulated deficit	(344,808,000)	(231,616,000)
Total stockholders’ equity	164,846,000	257,689,000
Total liabilities and stockholders’ equity	$ 214,035,000	$ 297,989,000