Anti-K5B antibodies enable researchers to detect and measure the K5B antigen in biological samples. This target is a reported synonym of the KRT78 gene, which encodes keratin 78. The human version of K5B has a canonical amino acid length of 520 residues and a protein mass of 56.9 kilodaltons, although 2 isoforms have been identified. It is reported to be notably expressed in the oral mucosa, esophagus, and cervix. K5B is a member of the Intermediate filament protein family.