The signature of immune cell subsets in HNSCC showed a dramatic decrease in median values of cytotoxic cells (−0.1418 vs. −0.0970, P = 0.0030), T cells (−0.2357 vs. −0.2056, P = 0.0010), CD8+ T cells (0.0730 vs. 0.0761, P = 0.1310), DC cells (−0.2267 vs. −0.1796, P < 0.001), and B cells (−0.1676 vs. −0.1373, P < 0.001), while MDSCs (0.0250 vs. −0.0058, P < 0.001) (Figure S4). Here, CD8A is linked to head and neck squamous cell carcinoma.