In head and neck squamous cell carcinoma (HNSCC), CD25high cells were enriched and represented 3% of CD3+CD4+ TILs compared to circulating CD3+CD4+ T cells of the same patients, which comprised 1% of CD3+CD4+ cells; circulating CD3+CD4+ T cells of normal controls comprised 0.4% of CD3+CD4+ cells [154]. The gene discussed is CD4; the disease is head and neck squamous cell carcinoma.