CTLA4 and gastric cancer: Among these, ICIs-mediated pathways, such as programmed death protein-1 (PD-1)/programmed death ligand-1 (PD-L1), cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), and lymphocyte activation gene-3 (LAG-3), have been extensively studied for the treatment of GC (Table 1).