What is the function of keratin in the epidermis?
The epidermis is the outer layer of the skin made of epithelial tissue. In the epidermis there are keratin-secreting cells (keratinocytes). Keratin is an insoluble protein that impregnates the surface of the skin providing protection and impermeability. In mammals keratin also forms the hairs.
The keratinized cells of the skin surface make the corneal layer. These cells die and are continuously changed by others.