Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities
Net loss	$ (21,413)	$ (18,835)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	946	893
Interest earned on marketable securities	220	170
Equity-based compensation	2,032	2,167
Non-operating lawsuit expense		1,398
Non-cash write-off of intangible assets	290
Changes in operating assets and liabilities:
Accounts and grants receivable	107	(164)
Prepaid expenses and other current assets	28	(122)
Other assets	51	(15)
Accounts payable	(1,113)	1,106
Deferred revenue		307
Non-operating lawsuit expense	(1,398)
Accrued expenses	1,502	(677)
Operating lease asset and liability	(254)	(197)
Net cash used in operating activities	(19,002)	(13,969)
Cash flows from investing activities:
Proceeds from the sale of marketable securities	8,880	179
Acquisition of property and equipment	(301)	(569)
Acquisition of intangible assets	(393)	(287)
Net cash provided by investing activities	8,186	(677)
Cash flows from financing activities:
Proceeds from the sale of private placements	5,338
Proceeds from warrants exercised	98
Proceeds from stock options issued		2
Equity issued for consulting services		(207)
Payments for taxes in RSUs vested	(174)	(304)
Net cash used in financing activities	5,262	(509)
Change in cash and cash equivalents	(5,554)	(15,155)
Cash and cash equivalents at beginning of period	10,503	25,658
Cash and cash equivalents at end of period	4,949	10,503
Supplemental Disclosure of Non-cash Investing and Financing Activities:
Vesting of RSUs into Class A Common Stock	(777)	(1,780)
Dividend attributable to down round feature of warrants	$ 798