Contrary to the previous standard of care (chemotherapy), the cytotoxic T-lymphocyte antigen 4 (CTLA-4) and programmed cell death 1 (PD-1) immune checkpoint inhibitors (ICIs) offer relatively well-tolerated and effective regimens that have improved survival outcomes across various malignancies including melanoma [1,2,3,4]. The gene discussed is PDCD1; the disease is melanoma.