SNAI1 and head and neck squamous cell carcinoma: Interestingly, under hypoxic conditions in which hypoxia-induced factor 1α (HIF-1α) binds to CSL, NICD, and MAML, higher expression of SNAIL, NOTCH receptors, and ligands was observed [289], suggesting an important role of hypoxia/NOTCH/EMT axis in the development of HNSCC.