The Company has operating leases for laboratory and office facilities in Bothell, Washington that expire in August 2027. The initial terms of the leases range from 6.5 to 7 years and the Company has options to extend the leases for an additional five years that it is not reasonably certain to exercise. Additionally, the Company has a lease agreement for laboratory and office facilities at the University of Washington in Seattle, Washington with an initial term of 12 months for which the Company recognizes expense on a straight-line basis within operating expenses. As of March 31, 2021, the Company was not party to any finance leases.

The following table reconciles the Company’s undiscounted operating lease cash flows to its operating lease liability (in thousands):

	March 31, 2021
Remaining 2021	$	262
2022		406
2023		418
2024		430
2025		443
Thereafter		767
Total undiscounted lease payments		2,726
Present value adjustment for minimum lease commitments		(615	)
Tenant improvement allowance receivable		(211	)
Net lease liability	$	1,900

The weighted average remaining lease term and the weighted average discount rate used to determine the operating lease liability were as follows:

March 31,

2021

Weighted average remaining lease term (years)

6.4

Weighted average discount rate

8.1

Operating lease expense was $61,000 for the three months ended March 31, 2021. Variable lease expense was $20,000 for operating leases during the three months ended March 31, 2021. Rent expense recognized for short term leases was $13,000 and $27,000 for the three months ended March 31, 2021 and 2020, respectively.