Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 33,334	$ 61,333
Accounts receivable	1,538	38,480
Short-term investments and related maturity receivables	316,400	374,894
Prepaid expenses and other current assets	12,902	27,367
Total current assets	364,174	502,074
Long-term investments	0	4,942
Property and equipment, net	101,707	110,020
Operating lease right-of-use assets	62,721	66,069
Restricted cash	15,177	15,227
Collaboration contract assets	0	7,196
Other assets	9	33
Total assets	543,788	705,561
Current liabilities:
Accounts payable	5,706	8,265
Accrued expenses	28,540	53,932
CIRM award liability, current portion	0	4,000
Deferred revenue	1,110	42,226
Operating lease liabilities, current portion	5,977	5,628
Total current liabilities	41,333	114,051
Operating lease liabilities, net of current portion	98,977	103,710
Stock price appreciation milestones	701	3,861
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $0.001 par value; authorized shares - 5,000,000 at September 30, 2023 and December 31, 2022; Class A Convertible Preferred shares issued and outstanding - 2,761,108 at September 30, 2023 and 2,794,549 December 31, 2022	3	3
Common stock, $0.001 par value; authorized shares - 250,000,000 at September 30, 2023 and December 31, 2022; issued and outstanding - 98,585,750 at September 30, 2023 and 97,294,917 at December 31, 2022	99	97
Additional paid-in capital	1,570,784	1,536,497
Accumulated other comprehensive loss	(499)	(1,854)
Accumulated deficit	(1,167,610)	(1,050,804)
Total stockholders’ equity	402,777	483,939
Total liabilities and stockholders’ equity	$ 543,788	$ 705,561