Common polymorphisms in two carcinogen detoxification genes, N-acetyltransferase 2 (NAT2) and glutathione-S-transferase M1 (GSTM1), have been consistently associated with bladder cancer risk and several studies suggested that the NAT2 slow acetylation genotype interacts with smoking intensity [3]. This evidence concerns the gene NAT2 and urinary bladder carcinoma.