GSTM1 and nasopharyngeal carcinoma: Regarding cancers, bladder cancer is increased to fourfold in North Tunisia among tobacco consumers (OR = 4.35, 95% IC 1.78–10.77, p-value = 6 × 10−4)61, nasopharyngeal carcinoma to twofold (Odds Ratio = 2.12, [0.64–4.7])62 and acute lymphoblastic leukemia to twofold (OR = 2.05, 95% IC 1.05–3.79, p-value = 3.1 × 10−2)63 in presence of GSTM1 null genotype.