Based on the developed prognostic model, we performed immune infiltration and immune function gene set enrichment analysis (GSEA), and also investigated the expression, methylation and mutation status of DNMT1, ZC3H12D, PD-1 and PD-L1 in HNSCC, and their effect on T-lymphocyte infiltration. This evidence concerns the gene PDCD1 and head and neck squamous cell carcinoma.