Based on our finding that Mysm1-deficient mice have several p53-dependent developmental anomalies, including altered skin structure and pigmentation – in part resembling mouse phenotypes commonly found upon deletion of genes, such as PAX3, MITF, and SOX10, associated with melanoma in humans [17] – we hypothesized that MYSM1 as well might be involved in tumorigenesis and melanoma. This evidence concerns the gene PAX3 and melanoma.