CTLA4 and metastatic melanoma: The anti-PD-1 antibodies pembrolizumab and nivolumab have shown promising results in patients with metastatic melanoma not harboring the mutation in the B-Raf proto-oncogene (BRAF-mutation) with improved survival rates when compared to the anti CTLA-4 antibody ipilimumab and chemotherapy [11,12,13].