Aldh1a1 has been associated to the cancer stem/tumor initiating cell phenotype in human sarcomas [8], nasopharylgeal carcinomas [9], breast carcinomas [10] and melanoma [11–13], and its level of expression and/or activity could represent a potential tool to identify stem-like cells in melanoma tumors [11, 14]. Here, ALDH1A1 is linked to cancer.