Table 1. Human FNDC5 variants information.

Variant	NCBI	Amino Acid	NCBI Description
FNDC5-1	NP_001165412.1	153	This variant (1) represents the longest transcript and encodes the shortest isoform (1).
FNDC5-2	NP_715637.2	212	This variant (2) contains multiple differences in the UTRs and coding region, compared to variant 1. It initiates translation from an alternate “AUA” start codon that is conserved as an “AUG” start codon in orthologs. The encoded isoform (2) is longer and has distinct N- and C-termini, compared to isoform 1.
FNDC5-3	NP_001165411.2	181	This variant (3) contains multiple differences in the UTRs and coding region, compared to variant 1. It initiates translation from an alternate “AUA” start codon that is conserved as an “AUG” start codon in orthologs. The encoded isoform (3) is longer and has distinct N- and C-termini, compared to isoform 1.