Keratin K5 is a member of the keratin gene family. Biochemically, most members of the CK family fall into one of two classes, type I (acidic polypeptides) and type II (basic polypeptides). The type II cytokeratins consist of basic or neutral proteins which are arranged in pairs of heterotypic keratin chains coexpressed during differentiation of simple and stratified epithelial tissues. The type II cytokeratins are clustered in a region of chromosome 12q12-q13. At least one member of the acidic family and one member of the basic family is expressed in all epithelial cells. Keratin K5 is expressed in normal basal cells. Synonyms: Monoclonal Keratin K5 antibody, Anti-Keratin K5 antibody, Cytokeratin 5 antibody, CK5 antibody, KRT5 antibody.