ESCs at the basal layer of the epidermis mostly differentiate into other epidermal cells [31, 48] They express high levels of α6 and β1 integrins, melanoma-associated chondroitin sulfate proteoglycan, and Leu-rich repeats and immunoglobulin-like domain 1 (LRIG1) [49, 50]. This evidence concerns the gene TWF1 and melanoma.