May play a role in the early stages of epithelial differentiation or in apoptosis. Expressed in hair follicle, corneal epithelium, epidermis and footpad epithelium (at protein level). Weakly expressed in outer cells of the two cell-layer ectoderm at embryonic day 14.5. Detected only in the intermediate cells, undetectable in the basal or outermost epidermal cells or the occasional follicular buds. In 17.5 dpc and 18.5 dpc epidermis expression is restricted to a single layer of suprabasal cells and is absent in the granular cell layer. Also present in the differentiated follicular cells at the apex of the 'horseshoeshaped' matrix. Detected throughout the limbal and corneal epithelium at day 1 of postnatal life, at day 5 of post-natal life it was no longer detected in the limbal epithelium.