GSTO2 and seminoma: Due to the biological origin and the clinically distinctive characteristics of the two large categories of testicular GCT, the individual effect of GSTO1*C419A (rs4925), GSTO2*A424G (rs156697), and GSTO2*A183G (rs2297235) polymorphisms on the risk for seminoma development was estimated as well (Supplementary Table S1).