While several studies have demonstrated that CD4+CD25+Foxp3+Treg may contribute to the progression of HNSCC and have a negative prognostic impact in HNSCC patients [127,128,129,130], several others presented contradictory results on the prognostic value of CD4+CD25+Foxp3+Treg TILs. Here, CD4 is linked to head and neck squamous cell carcinoma.