3. The matrixThe matrix, sometimes called the nail root is the growing area of the nail. The division of cells in this area forms it, which is part of the germinating layer of the epidermis. It lies under the eponychium, at the base of the nail, nearest to the body. The process of keratinisation takes place in the epidermal cells of the matrix, forming the hardened tissue of the nail plate. Function: To produce new nail cells.