In order to find the genes that are most critical to the TME in HNSCC, we combined the genes located in the middle node of the PPI network (Figure 3A) and the p-value less than 0.05 in the survival analysis to screen out four genes CCR5, CD3E, CD4, and HLA-DRB1. This evidence concerns the gene CCR5 and head and neck squamous cell carcinoma.