Over the last decade, immunotherapy has revolutionized the treatment of bladder cancer. The first anti-cancer drug targeting an immune checkpoint was ipilimumab, a CTLA4 blocker approved in the United States in 2011, while nivolumab and pembrolizumab (PD-1 inhibitors) were approved for urothelial carcinoma treatment in 2014 either as a single agent, in combination with other immunotherapy, or with chemotherapy and radiation therapy, with several clinical trials currently ongoing to optimize its use [4-10]. This evidence concerns the gene CTLA4 and urinary bladder cancer.