Immune checkpoint inhibitors that target the programmed cell death-1 (PD-1)/programmed cell death-ligand-1 (PD-L1) pathway have been shown to provide survival benefit in non-small cell lung cancer (NSCLC) compared with conventional standard therapy [1–6], and have become a standard treatment option for advanced-stage NSCLC. The gene discussed is PDCD1; the disease is non-small cell lung carcinoma.