Bladder cancer has a high prevalence of somatic mutations, a trait shared with cancers where chronic mutagen exposure plays a causal role (such as lung cancer and melanoma).7 Smoking is the main risk factor for bladder cancer with a hazard ratio of 2.33 for former smokers and 4.27 for current smokers.8 Following PAH exposure, incomplete hepatic metabolism leads to the excretion of bladder pro‐carcinogens in the urine9 where urothelial CYP‐activity could lead to DNA adduct formation and ultimately mutation. The gene discussed is PPIG; the disease is lung carcinoma.