Keratin 6C is a type II cytokeratin, one of a number of isoforms of keratin 6 encoded by separate genes located within the type II keratin gene cluster on human chromosome 12q. Keratins are the intermediate filament proteins that form a dense meshwork of filaments throughout the cytoplasm of epithelial cells. Keratins form heteropolymers consisting of a type I and a type II keratin. Keratins are generally expressed in particular pairs of type I and type II keratin proteins in a tissue-specific and cellular differentiation-specific manner.