GSTM1 and prostate cancer: When the data were analyzed in subgroups of subjects stratified by GSTM1 null/present genotypes, we found that the Ile105Val polymorphism was not significantly associated with prostate cancer risk among patients with GSTM1 null genotype (Val/Val+Val/Ile vs. Ile/Ile: OR = 1.11 95% CI = 0.75–1.65, P = 0.56; Table S2), and among patients with GSTM1 present genotype (Table S2).