While up to 20–30% of patients treated with anti-CTLA-4 or anti-PD-1 may experience durable cancer control, ~50% of metastatic melanoma patients treated with the combination of anti-CTLA-4 plus anti-PD-1 experience durable cancer control; however, immune related adverse events remain a problem93,94. The gene discussed is PDCD1; the disease is cancer.