Combinations of mAbs against PD-1 or its ligand [programmed cell death-ligand 1 (PD-L1)] with anticytotoxic T-lymphocyte-associated protein 4 (CTLA-4) mAbs have shown promise across a range of advanced solid tumors, including small-cell lung cancer,4 urothelial carcinoma,5 renal cell carcinoma,6 melanoma,7 non-small-cell lung cancer (NSCLC),8 and hepatocellular carcinoma.9 The gene discussed is CTLA4; the disease is non-small cell lung carcinoma.