Note 2 - Basis of Presentation, Principles of Consolidation and Significant Accounting Policies - Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Prepaid insurance	$ 589	$ 579
Vendor prepayments and deposits	486	1,281
Prepaid sponsored research	474	164
Non-trade receivables	23	1
Related party receivables	22	0
Total prepaid expenses and other current assets	$ 1,594	$ 2,025

The aggregate amount of receivables to be collected from related parties where one party can exercise control or significant influence over another party; including affiliates, owners or officers and their immediate families, pension trusts, and so forth, at the financial statement date. which are usually due within one year (or one business cycle).

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+ Details