CTLA4 and neoplasm: The greatest survival benefit in this study was observed when IL-15 was combined with anti-PD-L1 and anti-CTLA-4 treatment [25]; in a syngeneic murine colon cancer model, anti-PD-L1, when combined with ionizing radiation, effectively controlled tumor growth, which could not be achieved with either treatment alone, indicating synergy or an abscopal effect with radiation therapy [26].