Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 11,676	$ 21,765
Short-term investments	23,656	43,304
Accounts receivable, net of allowance for doubtful accounts of $0 as of December 31, 2015 and December 31, 2014	6,114	5,321
Inventory, current portion		34
Prepaid expenses and other current assets	1,608	1,784
Total current assets	43,054	72,208
Inventory, net of current portion	4,413	5,894
Property and equipment, net	15,735	19,106
Intangible assets, net	5,969	7,941
Other assets	506	288
Total assets	69,677	105,437
Current liabilities:
Accounts payable	848	862
Accrued liabilities	2,385	2,101
Accrued compensation and employee benefits	4,416	1,628
Deferred revenue	2,595	2,709
Related party deferred revenue		831
Note payable		2,000
Total current liabilities	10,244	10,131
Deferred revenue, net of current portion		1,103
Deferred rent, net of current portion	3,299	2,810
Note payable, net of current portion		21,000
Other long-term liabilities	35	128
Total liabilities	13,578	35,172
Stockholders' equity:
Common stock, par value $0.001 per share—200,000,000 shares authorized; 49,092,260 and 47,614,150 shares issued and outstanding as of December 31, 2015 and December 31, 2014, respectively	49	48
Additional paid-in capital	208,972	202,139
Accumulated other comprehensive loss	(24)	(37)
Accumulated deficit	(152,898)	(131,885)
Total stockholders' equity	56,099	70,265
Total liabilities and stockholders' equity	$ 69,677	$ 105,437