CD4 and head and neck squamous cell carcinoma: Prior works showed the presence of intratumoral HPV E6- and E7-specific CD4+ and CD8+ T cells, which predominantly secreted IFN-γ but also a substantial amount of IL-17, suggesting the intratumoral presence of HPV-specific TH1 and TH17 responses in HPV+ HNSCC (Figure 1) [83,131,132].