Because human urothelial tissue is rich in peroxidases, the aristolactams activated by peroxidase may result in the formation of the AL-DNA adducts in urothelial tissue [46, 47] and lead to A : T to T : A transverse mutations in the TP53 tumor suppression gene [38, 41, 47, 48], as demonstrated by overexpression of TP53 protein in patients with AAN and urothelial carcinoma [37]. The gene discussed is TP53; the disease is urothelial carcinoma.