CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 74,485	$ 51,175
Short-term investments	85,723	125,283
Accounts receivable, net	53,962	46,585
Inventories	60,469	49,073
Prepaid and other current assets	6,234	4,025
Total current assets	280,873	276,141
Property and equipment, net	37,626	32,923
Operating lease right-of-use assets	23,014	15,561
Other long-term assets	1,814	1,485
Total assets	343,327	326,110
Current liabilities:
Accounts payable	21,783	17,745
Accrued expenses	5,896	8,014
Employee-related liabilities	22,059	28,320
Deferred revenue	4,377	3,869
Common stock warrants	25,290	23,509
Operating lease liabilities	8,320	6,320
Other current liabilities	11,922	11,619
Total current liabilities	99,647	99,396
Operating lease liabilities - long-term	19,547	14,063
Other long-term liabilities	16,957	17,672
Total liabilities	136,151	131,131
Commitments and contingencies (Note 9)
Stockholders’ equity:
Common stock, $0.001 par value; 200,000 shares authorized, 60,071 and 59,396 shares issued and outstanding at March 31, 2020 (unaudited) and December 31, 2019, respectively.	60	59
Additional paid-in capital	847,056	819,626
Accumulated other comprehensive income (loss)	(245)	122
Accumulated deficit	(639,695)	(624,828)
Total stockholders’ equity	207,176	194,979
Total liabilities and stockholders’ equity	$ 343,327	$ 326,110