Immune checkpoint inhibitors (ICIs), including anti-cytotoxic T lymphocyte-associated antigen-4 (CTLA4) and anti-programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1), have dramatically altered the treatment landscape of NSCLC (3–8). The gene discussed is PDCD1; the disease is non-small cell lung carcinoma.