Findings from Garcia-Closas et al. (2005), from this study population, showed significant associations between bladder cancer and NAT2 slow acetylator compared with rapid/intermediate genotypes [OR (95% CI) of 1.4 (1.2–1.7)] and GSTM1 null (−/−) versus GSTM1 present genotypes [1.7 (1.4–2.0)]. This evidence concerns the gene GSTM1 and urinary bladder cancer.