TGFB1 and head and neck squamous cell carcinoma: The contribution of TGFβ signaling as a barrier compromising therapeutic response to cytotoxic therapy is exemplified by HPV-positive (HPV+) HNSCC (52), which have much better (70%) survival at 5 years compared to HPV-negative (HPV-) cancers that attain only 30% survival, even when HNSCC location and stage are similar.