In a phase III trial, 305 patients who had previously untreated advanced NSCLC with PD-L1 expression on at least 50% of tumor cells and no sensitizing mutation of the EGFR or translocation of the ALK gene, were randomly assigned to receive either pembrolizumab or the investigator’s choice of platinum-based chemotherapy. The gene discussed is ALK; the disease is non-small cell lung carcinoma.