Meta-analyses of epidemiological studies have associated the GSTM1 null genotype with enhanced risk of prostate cancer (28, 29) and cancer at other sites (30–32), and several epidemiological studies have reported that the beneficial effect of diets rich in cruciferous vegetables in reducing cancer risk is modified by GSTM1 genotype (33–37). Here, GSTM1 is linked to prostate cancer.