TME further inhibits tumor-infiltrating lymphocytes (TILs) due to the presence of immunosuppressive checkpoint molecules that bind the programmed death receptor 1 (PD-1) and cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4), which in turn, suppress the immune response (16, 19). The gene discussed is CTLA4; the disease is neoplasm.