The expression of four genes (HPRT1, CTNS, SHMT1, SLC38A7) was further verified by reverse transcription-polymerase chain reaction (RT–PCR) in patients with HNSCC and in vivo to validate their oncogenic role, and their relationships with the expression of immunological cell markers were also explored. The gene discussed is SLC38A7; the disease is head and neck squamous cell carcinoma.