Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 28,947	$ 87,176
Restricted cash, current portion	901	503
Short-term investments	201,586
Accounts receivable, net of allowance of $971 in 2015 and $527 in 2014	5,862	5,942
Inventory	8,093	11,542
Prepaid expenses and other current assets	5,337	1,314
Total current assets	250,726	106,477
Property and equipment, net	12,710	14,574
Restricted cash, long term portion	683	808
Other assets	1,121	1,764
Total assets	265,240	123,623
Current liabilities:
Accounts payable	7,332	8,867
Accrued compensation	8,552	5,980
Other accrued liabilities	18,708	10,341
Deferred revenue	144	112
Equipment loan, current portion		2,340
Short-term debt financing	42,090
Warrants	3,649	2,232
Total current liabilities	80,475	29,872
Equipment loan, long term portion		3,510
Senior secured term loan		20,964
Total long-term liabilities		24,474
Total liabilities	$ 80,475	$ 54,346
Commitments and contingencies (Note 6)
Convertible preferred stock issuable in series, $0.0001 par value: 50,000 and 51,233 shares authorized at December 31, 2015 and December 31, 2014, respectively, 0 and 31,397 shares issued and outstanding at December 31, 2015 and December 31, 2014, respectively; aggregate liquidation preference of $133,757 as of December 31, 2014		$ 240,612
Stockholders’ deficit:
Preferred stock, $0.0001 par value: 50,000 shares authorized; no shares issued and outstanding at December 31, 2015 and 2014, respectively
Common stock, $0.0001 par value: 750,000 and 82,000 shares authorized at December 31, 2015 and December 31, 2014, respectively, 50,346 and 6,879 shares issued and outstanding at December 31, 2015 and December 31, 2014, respectively	$ 5	$ 1
Additional paid in capital	436,259	8,664
Notes receivable from officers		(192)
Accumulated deficit	(250,083)	(179,808)
Accumulated other comprehensive loss	(1,416)
Total stockholders’ equity (deficit)	184,765	(171,335)
Total liabilities, convertible preferred stock, and stockholders’ equity	$ 265,240	$ 123,623