13. INCOME TAXES (Tables)

12 Months Ended

Dec. 31, 2022

Income Tax Disclosure Abstract

Schedule of Effective Income Tax Rate Reconciliation

The effective tax rate of our provision (benefit) for income taxes differs from the Federal statutory rate as follows:

	Year Ended December 31,
	2022			2021			2020
Statutory rate		21.0	%		21.0	%		21.0	%
Compensation related		(0.5	)%		(8.2	)%		0.0	%
Share-based compensation		(2.2	)%		25.1	%		0.0	%
Net operating loss expiration		(9.0	)%		(16.2	)%		(47.5	)%
Tax credits		1.5	%		1.4	%		2.2	%
Change in valuation allowance		(10.8	)%		(23.1	)%		24.3	%
Total		0.0	%		0.0	%		0.0	%

Schedule of Deferred Tax Assets

Deferred tax assets are summarized as follows (in thousands):

	December 31,
	2022			2021
Deferred tax assets
Reserves	$	651		$	634
Net operating loss carryforwards		92,469			90,593
R&D credit carryforwards		9,628			8,984
Depreciation/amortization deferred		19,787			17,417
Operating lease liabilities		3,292			1,222
Other		7,360			6,701
Total deferred tax assets		133,187			125,551
Deferred tax liabilities:
Operating lease right-of-use assets		(3,062	)		(1,171	)
Total deferred tax liabilities		(3,062	)		(1,171	)
Net valuation allowances		(130,125	)		(124,380	)
Deferred tax assets	$	—		$	—