CTLA4 and melanoma: In multiple murine tumor models, including the MC-38 and CT-26 colon tumors, the B16F10 melanoma and the RENCA renal cell cancer model, CPI-444 induced antitumor immune responses, and suppressed tumor growth as a single agent; it also augmented the efficacy of anti-PD-1/PD-L1 and anti-CTLA-4 agents [19].