T cells with the regulatory phenotype CD4+/CD25+/CD127low showed a higher percentage in the microenvironment of early stage HNSCC (14.4 ± 6.5%) compared to late stage HNSCC (8.9 ± 5.7%; p < 0.05; Figure 5B, middle plot). Here, CD4 is linked to head and neck squamous cell carcinoma.