The epidermal growth factor receptor (EGFR) plays an important role in the signaling that directs the behavior of epithelial cells. It is one of four transmembrane growth factor receptor proteins that share similarities in structure and function.
There are multiple ligands that bind to and activate EGFR. Ligand binding with EGFR results in receptor homo- or heterodimerization at the cell surface, followed by internalization of the dimerized receptor. After this step, autophosphorylation occurs followed by a cascade of downstream signals.