CTLA4 and neoplasm: This review comprehensively summarizes the advances in bladder cancer immunotherapy, focusing on the tumor immune microenvironment and emerging treatment modalities, as well as the roles of immune checkpoint inhibitors (ICIs) targeting PD-1/PD-L1 and CTLA-4 pathways, which have demonstrated remarkable efficacy in both muscle-invasive (MIBC) and non-muscle invasive bladder cancer (NMIBC).