TABLE 1.

BTB proteins containing a 3-box motif with high structural homology with the 3-box motif of IBtkα, as resulted from the Phyre2 computational tool-based bioinformatics analysis of secondary structure

The % identity column indicates the percentage identity between the C-terminal region of IBtkα BTB2 domain (aa 861–901) and the matched BTB protein. Confidence indicates the probability (from 0 to 100) that the match between the IBtkα sequence and the BTB protein is a true homology.

BTB proteins	% identity	Confidence	UniProt accession
	%
Specle-type POZ protein	41	98.2	O43791
Gigaxonin	15	96.8	Q9H2C0
Kelch repeat and BTB domain-containing protein 4	11	96.4	Q9NVX7
Kelch-like protein 11	32	96.4	Q9NVR0
BTB/POZ domain-containing protein 6	21	90.8	Q96KE9