Note 2 - Summary of Significant Accounting Policies - Estimated Useful Lives (Details)	12 Months Ended
Dec. 31, 2020
Laboratory Equipment [Member]
Laboratory equipment (in years) (Year)	5 years
Office Equipment [Member]
Laboratory equipment (in years) (Year)	3 years
Leasehold Improvements [Member]
Leasehold improvements	Shorter of remaining lease term or estimated useful life

Describes the periods of time over which an entity anticipates to receive utility from its property, plant and equipment (that is, the periods of time over which an entity allocates the initial cost of its property, plant and equipment).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 35
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=68071081&loc=d3e1205-110223

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=84158767&loc=d3e18780-107790

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration