Epidermal growth factor receptor (EGFR) is a type I transmembrane protein and receptor tyrosine kinase. EGFR has been shown to bind to some members of the EGF family ligands including EGF, amphiregulin, TGF-α, betacellulin, epiregulin, heparin-binding EGF, and neuregulin-2α. EGFR ligand binding induces homodimerization, as well as heterodimerization of EGFR with ErbB2 or with ligand-activated ErbB3 or ErbB4 (Schlessinger). Dimerization results in kinase activation, phosphorylation, and cell signaling, mediated primarily through MEK/ERF and AKT pathways (Navlonic et al.). EGFR signaling has been shown to regulate cell proliferation, differentiation, motility, and apoptosis. Elevated levels of EGFR have been correlated with carcinogenesis (Maihle et al.). Protein contains a His-residue tag at the carboxyl end of the polypeptide chain.