Fig. 2.

The EGFR signaling pathway, PI3K/AKT/mTOR pathway, MAPK pathway, STAT pathway, and MET pathway in head and neck cancer. EGFR epidermal growth factor receptor, TGF-α transforming growth factor-alpha, EGF epidermal growth factor, RTKs receptor tyrosine kinases, HER2/3 human epidermal growth factor receptor 2/3, c-MET c‑mesenchymal–epithelial transition factor, IGF-1R insulin-like growth factor 1 receptor, PGE2 prostaglandin E2, GPCR G-protein-coupled receptor, PLCγ phospholipase c-γ, PKC protein kinase C, JAK Jenus-activated kinase; STAT3/5, signal transducer and activator of transcription 3/5, PTEN phosphatase and tensin homolog, PI3K phosphoinositide 3-kinase, PIP2 phosphatidylinositol 4,5-bisphosphate, PIP3 phosphatidylinositol 3,4,5-trisphosphate, AKT serine/threonine-specific protein kinase, mTOR mammalian target of rapamycin, DNMT-1 DNA methyltransferase 1, SOS son of sevenless, GRB2 growth factor receptor-bound protein 2, SHC SRC homology domain c-terminal adaptor homolog, ERK: extracellular signal-regulated kinase, MAP2K6 mitogen-activated protein kinase–kinase 6, PAK1 p21-activated kinase 1, DUSP dual-specificity phosphatases, PCNA proliferation cell nuclear antigen, DNA-PK DNA-dependent protein kinase