CTLA4 and cancer: The use of programmed death 1 (PD-1)/programmed death ligand 1 (PD-L1) or cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) immune checkpoint inhibitors (ICIs) has become a standard in the treatment of various cancers, including NSCLC [13,14,56,73], with significant clinical benefits.