The epidermal growth factor receptor (EGFR) is a membrane spanning tyrosine kinase receptor for epidermal growth factor (EGF) and other ligands of the EGF family such as TGF-alpha, amphiregulin, betacellulin, epiregulin and heparin-binding EGF-like growth factor. Upon ligand binding, the EGFR homodimerizes or heterodimerizes with other ErbB receptor family members and tranduces a downstream signal via the ras-raf-mitogen activated protein kinase pathway or the phosphatidylinositol 3-kinase (PI3K)/Akt pathway. Signals from the EGFR function to influence cell proliferation, differentiation, and development.
