The Company’s lease portfolio is comprised of operating leases for laboratory, office and manufacturing facilities located in South San Francisco, California, Seattle, Washington and Bothell, Washington with contractual periods expiring between December 2021 and March 2031. In addition to minimum rent, the leases require payment of real estate taxes,

insurance, common area maintenance charges and other executory costs. These additional charges are considered variable lease costs and are recognized in the period in which the costs are incurred.

The following table summarizes the Company’s future minimum operating lease commitments, including expected lease incentives to be received, as of September 30, 2021 (in thousands):


Year ending December 31:
2021 (remaining three months)	$	2,419
2022		10,698
2023		11,018
2024		11,347
2025		11,859
Thereafter		60,302
Total undiscounted lease payments		107,643
Less: imputed interest		(33,422	)
Less: tenant improvement allowances		(6,993	)
Total operating lease liabilities	$	67,228

Reported as of September 30, 2021:
Short-term portion of lease liabilities (included in accrued liabilities and other current liabilities)	$	1,544
Operating lease liabilities, non-current		65,684
Total	$	67,228

The operating lease costs for all operating leases were $2.4 million and $2.9 million for the three months ended September 30, 2021 and 2020, respectively, and $7.1 million and $8.3 million for the nine months ended September 30, 2021 and 2020, respectively. The operating lease costs and total commitments for short-term leases were de minimis for the three and nine months ended September 30, 2021 and 2020. Variable lease costs for operating leases were $1.4 million and $0.5 million for the three months ended September 30, 2021 and 2020, respectively, and $3.7 million and $1.5 million for the nine months ended September 30, 2021 and 2020, respectively.

In May 2021, the Company entered into a sublease, whereby the Company agreed to sublease approximately 11,000 rentable square feet of its space in South San Francisco, California currently leased by the Company. The sublease commenced in August 2021, is classified as an operating lease and will expire in March 2031. The monthly fixed payment due to the Company is $0.1 million, subject to annual rent increases in accordance with the contract.

In September 2021, the Company entered into a sublease with Sonoma Biotherapeutics, Inc. ("Sonoma"), a related party, whereby the Company agreed to sublease approximately 18,000 rentable square feet of space in South San Francisco, California currently leased by the Company. See Note 13, Related-Party Transactions. As a part of the sublease, in September 2021, the Company received a $4.6 million tenant improvement contribution payment, which will be recognized over the term of the sublease. The sublease commenced in September 2021, is classified as an operating lease and will expire in March 2031. The monthly fixed payment due to the Company is $0.1 million, subject to annual rent increases in accordance with the contract.