CD8A and head and neck squamous cell carcinoma: In total HNSCC patients, the infiltration of CD8 T cells, dendritic cells and macrophages were not statistically significant (P > 0.05) (Fig. 11e,g,i), while CD8 T cells, dendritic cells and macrophages infiltration levels were significantly negatively correlated with the risk score in the HPV- patients (P < 0.05) (Fig. 11f,h,j).