However, the impressive effects of ipilimumab in melanoma patients did not proceed in renal cell carcinoma,350 NSCLC,351 small-cell lung cancer352 and prostate cancer.353 Another CTLA-4-blocking antibody, tremelimumab, has not received FDA approval since it did not improve survival compared to chemotherapy in metastatic melanoma.354 As the first immune-checkpoint inhibitor, ipilimumab is also currently the only CTLA-4-blocking antibody that has gained approval for anticancer treatment. Here, CTLA4 is linked to metastatic melanoma.