This CCDS represents a TPI variant that uses an upstream promoter compared to the CCDS8566.1 representation. Data in PMIDs 4022011, 2925688, 2243103 and 10575546 support the presence of the internal promoter used by the CCDS8566.1 variant. The use of the upstream promoter is supported by human transcript data, including M10036.1, AL517115.3 and DB444195.1, as well as homologous transcripts. This longer transcript also uses an upstream start codon, resulting in an isoform that is 37 aa longer at the N-terminus compared to the CCDS8566.1 isoform. The sequence encoding the longer N-terminus is conserved in most mammalian species.