CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 66,271	$ 87,784
Short-term investments	275,186	37,534
Prepaid expenses and other current assets	5,820	1,861
Total current assets	347,277	127,179
Property and equipment, net	23,728	10,858
Operating lease right-of-use assets	25,070
Intangible assets	1,320	1,320
Goodwill	4,228	4,228
Other long-term assets	3,548	3,411
Total assets	405,171	146,996
Current liabilities:
Accounts payable	1,256	4,929
Accrued and other liabilities	24,315	13,926
Operating lease liabilities, current	4,199
Term debt - short-term		3,000
Total current liabilities	29,770	21,855
Term debt - long-term	29,059	26,140
Deferred CIRM grant liability	23,755	19,592
Warrant liability		1,271
Deferred tax liability	55	55
Operating lease liability, non-current	25,615
Other long-term liabilities	1,081	5,421
Total liabilities	109,335	74,334
Commitments and contingencies (Note 10)
Convertible preferred stock (Series A, A-1, B, C and D), $0.0001 par value: 0 and 33,085,827 shares authorized at September 30, 2020 and December 31, 2019, respectively; 0 and 32,934,785 shares issued and outstanding at September 30, 2020 and December 31, 2019, respectively		222,173
Stockholders’ equity (deficit):
Common stock, $0.0001 par value: 250,000,000 and 57,013,463 shares authorized at September 30, 2020 and December 31, 2019, respectively; 61,819,509 and 13,196,419 shares issued and outstanding as of September 30, 2020 and December 31, 2019, respectively	6	2
Additional paid-in capital	541,605	2,689
Accumulated other comprehensive income (loss)	(39)	19
Accumulated deficit	(245,736)	(152,221)
Total stockholders’ equity (deficit)	295,836	(149,511)
Total liabilities, convertible preferred stock and stockholders’ equity (deficit)	$ 405,171	$ 146,996