Skin cell. Coloured scanning electron micrograph (SEM) of the surface of a single squamous skin cell (squame). These cells overlap one another to form the outermost layer of the skin. This cell does not yet contain keratin. The surface is covered in microplicae or microfolds. Microplicae may function in increasing adhesion between cells, in reducing the frictional area in cells subjected to wear and tear, or in trapping lubricating fluids, for example mucin, to keep the skin surface moist. As squame cells reach the surface of the skin, they become keratinized and are eventually shed by the process of desquamation.