Condensed Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 20,222	$ 14,941
Short-term investments	51,148	61,170
Contract and other receivables	532	1,657
Prepaid materials, net	5,912	5,552
Prepaid expenses and other current assets	1,752	4,154
Total current assets	79,566	87,474
Property and equipment, net	10,172	11,830
Intangibles, net	802	1,015
Other assets	307	342
Total assets	90,847	100,661
Current liabilities:
Accounts payable	5,229	5,840
Accrued liabilities	4,770	5,577
Accrued compensation	1,687	2,318
Current portion of deferred revenue	72	72
Total current liabilities	11,758	13,807
Term loan, less debt issuance costs	19,845	19,802
Deferred revenue, less current portion	1,939	1,993
Deferred rent, less current portion	8,372	8,840
Other long-term liabilities	351	144
Total liabilities	42,265	44,586
Commitments and Contingencies
Stockholders’ equity:
Common stock, $0.001 par value; 200,000,000 shares authorized, 103,955,147 and 52,924,805 shares issued and outstanding at September 30, 2017 (unaudited) and December 31, 2016, respectively	104	53
Additional paid-in capital	379,992	329,496
Accumulated other comprehensive loss	(104)	(123)
Accumulated deficit	(331,410)	(273,351)
Total stockholders’ equity	48,582	56,075
Total liabilities and stockholders’ equity	$ 90,847	$ 100,661