The epidermal growth factor receptor (EGFR), also known as ErbB1 and HER1, a type I transmembrane glycoprotein. It exists on the cell surface and is activated by binding of its specific ligands, including EGF and TGF-α. EGFR signaling plays a crucial role in the regulation of cell proliferation, survival and differentiation. Binding of a ligand induces EGFR homo- or hetero- dimerization, initiates subsequent tyrosine autophosphorylation and various downstream pathways (MAPK, PI3K/PKB and STAT).
Activation of the receptor is important for the innate immune response in human skin. Mutations that lead to EGFR overexpression (known as upregulation) or overactivity have been associated with a number of cancers, including lung cancer, anal cancers and glioblastoma multiforme. Aberrant EGFR signaling has been implicated in psoriasis, eczema and atherosclerosis. Currently, EGFR was proposed as a target for cancer therapy.