PDCD1 and melanoma: The development of immune checkpoint inhibitors and BRAF- and MEK-targeted therapies has led to a transformation of survival outcomes in patients with advanced melanoma.1 In particular, the programmed cell death 1 inhibitors nivolumab and pembrolizumab and the cytotoxic T-lymphocyte–associated protein-4 blocking antibody ipilimumab have reshaped immunologic approaches to the treatment of this disease.