CTLA4 and cancer: The advent of immune checkpoint inhibitors (ICIs) targeting programmed death-1 (PD-1)/PD-ligand 1 (PD-L1) and cytotoxic T lymphocyte antigen 4 (CTLA-4) have revolutionized cancer therapy due to their ability to utilize the body’s own immune system to identify and destroy cancer cells [10,11,12,13].