We would like to thank Dr Osamu Ogawa (Department of Urology, Kyoto University, Japan) for providing human bladder cancer cell lines, Dr Katsumi Imaida (Onco-Pathology, Department of Pathology and Host-Defense, Kagawa University, Japan) for the anti-CYP2A6 antibody, and Naomi Kasuga (Department of Nephro-Urology, Nagoya City University, Japan) for technical assistance. The gene discussed is CYP2A6; the disease is urinary bladder cancer.