Pembrolizumab is a programmed death receptor-1 (PD-1) blocking antibody approved for the treatment of metastatic melanoma that has progressed past cytotoxic T-lymphocyte antigen 4 (CTLA-4) inhibitor Ipilimumab and BRAF inhibitors such as vemurafenib or dabrafenib (if BRAF mutated). Here, BRAF is linked to metastatic melanoma.