Epidermal Growth Factor Receptor
The epidermal growth factor receptor (EGFR) is the prototype cell surface receptor for the epidermal growth factor (EGF) family of soluble protein ligands. The receptor itself is part of a family of homologous transmembrane tyrosine kinase receptors that includes EGFR (ErbB-1), HER2/c-neu (ErbB-2), Her 3 (ErbB-3), and Her 4 (ErbB-4). EGFR is a 1186aa, 134 kD protein and was the first receptor described to have intrinsic tyrosine kinase activity directed toward not only to itself (autophosphorylation) but also to various downstream target proteins. Following binding of its ligands, EGFR can elicit intracellular signals that modulate a wide variety of cellular functions including cell proliferation, survival, migration, and differentiation. The EGFR gene maps to chromosome 7p11-13, and it is often amplified or rearranged in glioblastoma multiforme, non-small cell lung cancer, and prostate cancer.