Keratin 19 is a type I keratin. The type I cytokeratins consist of acidic proteins which are arranged in pairs of heterotypic keratin chains. Unlike its related family members, this smallest known acidic cytokeratin is not paired with a basic cytokeratin in epithelial cells. It is specifically found in the periderm, the transiently superficial layer that envelops the developing epidermis. The type I cytokeratins are clustered in a region of chromosome 17q12-q21. Alternative Names: KRT19 protein, Keratin K-19, CK19 protein, Keratin K-19 protein, Keratin K 19 protein, Keratin K 19, Keratin 19 protein, Cytokeratin 19 protein, K19 protein, K1CS protein, MGC15366 protein, Keratin K19