CD8A and head and neck squamous cell carcinoma: Comparison between PBMC HNSCC and PBMC HC revealed a significant decrease of the [CD8+] / [CD4+/CD25+/CD127low] ratio in PBMC of HNSCC patients (7.8 ± 6.4 vs. 29.1 ± 31.5; p < 0.005; Figure 1F, left plot).