Progress of immune checkpoint inhibitors in gastric cancer

Figure 1 Mechanism of immune checkpoint inhibitors. Blocking programmed death 1, programmed death ligand 1, and cytotoxic T lymphocyte-associated protein 4 can activate T cells, leading to the death of tumor cells. APC: Antigen-presenting cell; CTLA-4: Cytotoxic T lymphocyte-associated protein 4; GC: Gastric cancer; MHC: Major histocompatibility complex; PD-1: Programmed death 1; PD-L1: Programmed death ligand 1; TCR: T cell receptor.