Results demonstrated that most of the five genes were significantly correlated with immune checkpoint genes (BTLA, CD274, CTLA4, HAVCR2, LAG3, PDCD1, and TIGIT) and cytotoxic genes (granzyme A [GZMA], GZMB, GZMK, GZMM, interferon-gamma [IFNG], perforin 1 [PRF1], and tumor necrosis factor superfamily member 11 [TNFSF11]), which revealed that these genes might play an important role in tumor immunity. The gene discussed is PDCD1; the disease is neoplasm.