PDCD1 and melanoma: The standard of care treatments approved by the US Food and Drug Administration (FDA) for first-line (1L) treatment of melanoma include anti-programmed cell death protein 1 (PD-1) monotherapies, the combination of anti-PD-1 and anti-CTLA-4 therapy, and more recently the combination of anti-PD-1 and anti-LAG-3 therapy as well as BRAF/MEK inhibitors for patients with BRAF mutation (BRAF-MT) (6–8)