CAT and urinary bladder cancer: To reach this objective, we performed a search on PubMed, Medline, and Google Scholar for articles in English published up to May 2018 using the following keywords: oxidative stress, antioxidants; catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GTPx), reactive oxygen species (ROS), reactive nitrogen species (RNS), lipid peroxidation, paraoxonases (PONs), urinary bladder cancer, and nitric oxide.