CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 18,400	$ 8,346
Other current assets	1,324	829
Total current assets	19,724	9,175
Property and equipment, net	1,477	1,820
Operating lease right-use-of assets	341	636
Goodwill	372	372
Intangible assets, net	51	86
Other assets	16	16
Total assets	21,981	12,105
Current liabilities:
Accounts payable and accrued expenses	4,151	2,081
Operating lease liability	111	123
Term loan obligation, current	1,608	6,335
Total current liabilities	5,870	8,539
Noncurrent operating lease liability	269	528
Term loan obligation	5,005
Warrant liability	1	7
Total liabilities	11,145	9,074
Commitments and contingencies (Note 7)
Stockholders’ equity:
Preferred stock, $0.001 par value; 5,000,000 shares authorized; 1,952 and 1,954 shares issued and outstanding in 2021 and 2020, respectively
Common stock, $0.001 par value; 100,000,000 shares authorized; 15,510,025 and 6,749,028 shares issued and outstanding in 2021 and 2020, respectively	16	7
Additional paid-in capital	457,730	436,535
Accumulated deficit	(446,910)	(433,511)
Total stockholders’ equity	10,836	3,031
Total liabilities and stockholders’ equity	$ 21,981	$ 12,105

Sum of the carrying values as of the balance sheet date of obligations incurred through that date and due within one year (or the operating cycle, if longer), including liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received, taxes, interest, rent and utilities, accrued salaries and bonuses, payroll taxes and fringe benefits.

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- Definition

Amount of excess of issue price over par or stated value of stock and from other transaction involving stock or stockholder. Includes, but is not limited to, additional paid-in capital (APIC) for common and preferred stock.