In 2015, the Company entered into a noncancelable operating lease for approximately 31,280 square feet of space used for its current laboratory operations. In 2020, the lease term was extended through November 2027 and includes an option to extend the term for a period of three years at prevailing market rates. The Company determined the extension option is not reasonably certain to be exercised. The lease contains a leasehold improvement incentive and escalating rent payments. In 2021, the Company amended the lease to expand the leased premises by an additional 14,710 square feet of space (the “Expansion Lease”). The Expansion Lease expired at the end of December 2022 and was not extended.

In 2019, the Company entered into a noncancelable three-year operating lease for a co-located data center space. In 2022, the lease term was extended through September 2025 and includes an option to extend the term for a period of three years immediately following the expiration of the term. The Company determined the extension option is not reasonably certain to be exercised.

In 2021, the Company entered into a noncancelable operating lease for approximately 100,000 square feet of space in Fremont, California used for its corporate headquarters and expanded laboratory facility. The lease term is 13.5 years and commenced in October 2022. The Company gained early access to the premises upon entering the lease for the purpose of constructing and installing tenant improvements, for which the landlord contributed $15.1 million. Such contributions were accounted for as lease incentives and are recognized as reductions to lease expense over the remainder of the lease term. The lease expires at the end of March 2036 and includes two options to extend the term for a period of five-years per option at prevailing market rates. The Company determined the extension options are not reasonably certain to be exercised. The lease also contains escalating rent payments.

The Company also has a noncancelable operating lease for approximately 5,100 square feet of space in Shanghai, China used for its China operations, which expires on June 30, 2024, as well as various other short-term leases.

Components of lease cost were as follows (in thousands):


	Three Months Ended March 31,
	2023		2022
Lease cost
Operating lease cost	$	1,749	$	2,174
Short-term lease cost		99		29
Variable lease cost		493		261
Total lease cost	$	2,341	$	2,464

As of March 31, 2023, the Company’s operating leases had a weighted-average remaining lease term of 11.0 years and a weighted-average discount rate of 10.5%. The Company’s discount rates are based on estimates of its incremental borrowing rate, as the discount rates implicit in the leases cannot be readily determined. Future lease payments under operating leases as of March 31, 2023 were as follows (in thousands):


	Amount
2023 (remaining nine months)	$	4,907
2024		7,895
2025		7,808
2026		7,168
2027		7,189
2028 and thereafter		48,013
Total future minimum lease payments		82,980
Less: imputed interest		(36,142	)
Present value of future minimum lease payments		46,838
Less: current portion of operating lease liability		(6,529	)
Long-term operating lease liabilities	$	40,309

Cash paid for operating lease liabilities, included in cash flows from operating activities in the condensed consolidated statements of cash flows, for the three months ended March 31, 2023 and 2022, was $0.8 million and $0.9 million, respectively.