CD4 and head and neck squamous cell carcinoma: As our transcriptional analysis of CD4+ T cells in HNSCC tumors revealed an increased CD4+ TFH cell signature in HPV+ HNSCC, we sought to interrogate the frequencies of CD4+ Tconv lineages (i.e. TFH, TH1, regulatory TFH, and Tregs) present in HNSCC patients by flow cytometry.