In particular for metastatic melanoma and metastatic renal cell carcinoma (RCC), ICI compare favorably in terms of response rates (approximate ORR on anti-PD-1 mAb in RCC: 25%; in melanoma: 40 and 58% when combined with anti-CTLA-4 mAb) (4, 10, 11, 41). Here, CTLA4 is linked to metastatic melanoma.