Eight tumor-related immunosuppressive molecules, CD274, CTLA4, HAVCR2, LAG3, PDCD1 (PD1), PDCD1LG2, SIGLEC15, and TIGIT, had higher expression in HNSCC tumor tissues compared with HNSCC normal tissues. The gene discussed is SIGLEC15; the disease is head and neck squamous cell carcinoma.