ALDH1A1 and melanoma: Some ALDHs, particularly ALDH1A1, ALDH1A3, and ALDH3A1, are widely regarded as markers of stemness in normal tissues (basal skin, bronchial mucosa cells, human cornea, breast, liver), as well as in several solid tumors (non-small-cell lung cancer (NSCLC), melanoma, gastric, breast) [5,6,7,8,9].