Keratin 4
Keratin, type I cytoskeletal 4 also known as cytokeratin-4 or keratin-4 is a protein that in humans is encoded by the KRT4 gene.
Keratin 4 is a type [II cytokeratin]. It is specifically found in differentiated layers of the mucosal and esophageal epithelia together with keratin 13. Mutations in the genes encoding this protein have been associated with White [Sponge Nevus], characterized by oral, esophageal, and anal leukoplakia.