CTLA4 and cancer: The landscape of cancer treatment has undergone a transformative shift with the advent of immunotherapy, substantially reducing mortality rates, extending overall survival (OS), and prolonging progression-free survival (PFS).[5] Immune checkpoint inhibitors (ICIs) have played a pivotal role in this transformation, bolstering the body’s immune response against cancer cells by inhibiting antibodies such as cytotoxic T-lymphocyte antigen 4 (CTLA-4) and programmed cell death protein 1 (PD-1), or its ligand (PD-L1).[6] However, the remarkable potential of immunotherapy comes with a dual nature.