Moreover, transient anoxia-mediated downregulation of the EGFR-triggered Ras-MAPK- and PI3K/AKT-pathway, albeit with unchanged EGFR protein levels, was confirmed in 3 HNSCC cell lines (Cal-33, SCC-131, and SCC-263) in vitro. This evidence concerns the gene AKT1 and head and neck squamous cell carcinoma.