Abundant evidence exists on the involvement of two tightly interconnected MAPK/ERK and PI3K/Akt/mTOR signaling pathways in regulating various hallmarks of cancer cells, like proliferation, stress response, invasion, metastasis, and EMT in different tumor types, including HNSCC [30,32,38,49,50,51,52,53]. This evidence concerns the gene MTOR and head and neck squamous cell carcinoma.