As a monotherapy, some of the best responses were observed in melanoma (objective response rate (ORR) of 45%) (3), PDL1-positive non-small cell lung cancer (NSCLC; ORR 45%) (4–6) and multiple Mismatch-Repair deficient (MMRd) tumor types (ORR of 40-53%) (7–9). The gene discussed is CD274; the disease is melanoma.