Figure 1. Signaling pathways in HNSCC invasion involving the EGFR.
Epidermal growth factor receptor (EGFR), activated by EGFR ligands, can activate ERK/AP1, PI3K/Akt, or Src activity, which all lead to increased invasion in head and neck cancer. EGFR can be cross-activated by GCPRs, whose downstream signaling leads to the release of EGFR ligands from their transmembrane precursors through activity by the ADAM family of proteases.