This finding in RCC models differed from the results seen previously in the mouse YUMMER1.7 melanoma model, where DR-18 + anti–PD-1 had increased antitumor effects (12), although in the YUMMER1.7 model enhanced activity was still seen with DR-18 + anti–CTLA-4. The gene discussed is CTLA4; the disease is renal cell carcinoma.