Balance Sheets - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 14,941,000	$ 15,960,000
Short-term investments	61,170,000	98,103,000
Restricted cash	0	1,256,000
Contract and other receivables	1,657,000	10,021,000
Prepaid materials, net	5,552,000	5,543,000
Prepaid expenses and other current assets	4,154,000	3,375,000
Total current assets	87,474,000	134,258,000
Property and equipment, net	11,830,000	5,400,000
Intangibles, net	1,015,000	1,081,000
Other assets	342,000	344,000
Total assets	100,661,000	141,083,000
Current liabilities:
Accounts payable	5,840,000	2,717,000
Accrued liabilities	5,577,000	6,329,000
Accrued compensation	2,318,000	2,392,000
Current portion of deferred revenue	72,000	1,194,000
Total current liabilities	13,807,000	12,632,000
Term loan, less debt issuance costs	19,802,000	0
Deferred revenue, less current portion	1,993,000	2,065,000
Deferred rent, less current portion	8,840,000	2,308,000
Other long-term liabilities	144,000	0
Total liabilities	44,586,000	17,005,000
Commitments and Contingencies (Note 8)
Stockholders’ equity:
Common stock, $0.001 par value; 200,000,000 shares authorized, 52,924,805 and 52,669,266 shares issued and outstanding at December 31, 2016 and 2015, respectively	53,000	53,000
Additional paid-in capital	329,496,000	315,673,000
Accumulated other comprehensive loss	(123,000)	(133,000)
Accumulated deficit	(273,351,000)	(191,515,000)
Total stockholders’ equity	56,075,000	124,078,000
Total liabilities and stockholders’ equity	$ 100,661,000	$ 141,083,000