By targeting cell-surface receptors such as cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and programmed cell death protein 1 (PD-1) or its ligand PD-L1—receptors upregulated by tumor cells to evade immune surveillance—these agents allow the immune system to recognize and destroy cancer cells.2 Here, CTLA4 is linked to neoplasm.