Considering that high frequency of polymorphisms of CYP2D6 or the polymorphism of VDR, and null for GSTM1 gene in melanoma patients [55-57], it is plausible that changes in GSTM1, CYP2D6 and VDR genes may increase the risk for both PD and melanoma. The gene discussed is CYP2D6; the disease is Parkinson disease.