Condensed Consolidated Balance Sheets (unaudited) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 113,957	$ 72,280
Short-term marketable securities	157,385	149,040
Accounts receivable	14,640	12,787
Inventory	7,075	7,287
Prepaid expenses and other current assets	4,024	1,541
Total current assets	297,081	242,935
Long-term marketable securities	2,963	73,254
Property and equipment, net	30,318	16,036
Deferred offering costs	4,257	0
Other assets	1,936	1,974
Total Assets	344,599	342,938
Current liabilities:
Accounts payable	13,081	4,998
Accrued compensation	7,430	4,911
Accrued expenses	7,482	6,406
Capital lease, current	102	199
Deferred revenue	3,955	3,113
Total current liabilities	32,050	19,627
Capital lease, net of current portion	137	460
Deferred rent, net of current portion	7,623	6,537
Obligation related to royalty	7,446	7,708
Other long-term liabilities	206	0
Total Liabilities	47,462	34,332
Commitments and contingencies (Note 8)
Redeemable noncontrolling interest	41,950	0
Stockholders’ equity:
Convertible preferred stock, par value of $0.00001 per share; 80,104,464 shares authorized as of September 30, 2018 and December 31, 2017; 78,627,369 shares issued and outstanding as of September 30, 2018 and December 31, 2017 with aggregate liquidation preference of $501,410 as of September 30, 2018	499,974	499,974
Common stock, par value of $0.00001 per share; 111,853,396 shares authorized as of September 30, 2018 and December 31, 2017; 13,002,822 and 11,896,882 shares issued and outstanding as of September 30, 2018 and December 31, 2017	0	0
Additional paid-in capital	11,421	4,900
Accumulated other comprehensive loss	(531)	(532)
Accumulated deficit	(255,677)	(195,736)
Total Stockholders’ Equity	255,187	308,606
Total Liabilities, Redeemable Noncontrolling Interest and Stockholders’ Equity	344,599	342,938
Patent Licensing Agreement
Current assets:
Capitalized license fees	$ 8,044	$ 8,739