Because many of the selenoproteins function as antioxidants, we reasoned that maximizing the activities of these proteins by topical treatment with supplemental selenomethionine (SeMet) might prevent melanoma, especially at the initiation stage [25] when normal melanocytes (the cells from which melanomas arise) in the skin are under severe genotoxic and oxidative stress. The gene discussed is SELENOS; the disease is melanoma.