Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	[1]
Current assets:
Cash and cash equivalents	$ 390,260	$ 173,415
Short-term investments	436,666	555,231
Receivable from collaboration partners ($4,924 and $943 from a related party)	5,235	1,049
Accrued interest receivable	1,029	649
Prepaid expenses and other current assets	8,680	5,471
Total current assets	841,870	735,815
Long-term investments	57,986	6,440
Property and equipment, net	14,849	10,807
Right-of-use assets	12,243	12,781
Restricted cash	1,988	203
Other long-term assets	6,183	6,246
Total assets	935,119	772,292
Current liabilities:
Accounts payable	24,544	15,682
Accrued research and development expenses	23,023	18,307
Other accrued liabilities	7,536	9,543
Deferred revenue, current ($67,571 and $67,571 to a related party)	74,571	74,571
Other current liabilities	2,381	3,566
Total current liabilities	132,055	121,669
Deferred revenue, noncurrent ($110,097 and $117,808 to a related party)	113,369	122,830
Operating lease liabilities, noncurrent	14,706	15,243
Other long-term liabilities ($9,703 and $9,703 to a related party)	10,199	10,246
Total liabilities	270,329	269,988
Commitments (Note 10)
Stockholders’ equity:
Preferred stock, $0.0001 par value, 10,000,000 shares authorized as of March 31, 2021 and December 31, 2020; no shares issued and outstanding as of March 31, 2021 and December 31, 2020	0	0
Common stock, $0.0001 par value, 400,000,000 shares authorized as of March 31, 2021 and December 31, 2020; 70,965,513 and 65,114,685 shares issued and outstanding as of March 31, 2021 and December 31, 2020, respectively	7	6
Additional paid-in capital	1,065,562	830,438
Accumulated deficit	(400,777)	(328,184)
Accumulated other comprehensive (loss) income	(2)	44
Total stockholders’ equity	664,790	502,304	[2]
Total liabilities and stockholders’ equity	$ 935,119	$ 772,292

[1] The Condensed Consolidated Balance Sheet as of December 31, 2020 has been derived from the audited financial statements as of that date.

[2] The balances as of December 31, 2020 and 2019 have been derived from the audited financial statements as of that date.