Immunotherapy, such as cytotoxic T lymphocyte associated antigen 4 (CTLA4), programmed death-1 (PD-1) and programmed death ligand-1 (PD-L1) inhibitors, showed promising antitumor effects in malignant melanoma and non-small-cell lung carcinoma (NSCLC) (3, 4). The gene discussed is PDCD1; the disease is non-small cell lung carcinoma.