For both HPV− HNSCC subtypes, the ratios of IM_stroma PD-1+CD8+ TILs to TC_stroma (subarea stroma of TC) PD-1+CD8+ TILs were higher than those of PD-1+CD8− TILs (Fig. 3e, k). This evidence concerns the gene CD8A and head and neck squamous cell carcinoma.