EGFR (Epidermal growth factor receptor, ErbB-1) is a receptor tyrosine kinase (RTK) that is one of four members of the EGFR/ErbB family of receptor tyrosine kinases. EGFR plays a key role in the regulation of essential normal cellular processes and in the pathophysiology of hyperproliferative diseases such as cancer. Activation of the EGFR signaling pathway has been linked with increased cell proliferation, angiogenesis, metastasis and decreased apoptosis. EGFR carboxy-terminal residues Ser1046 and Ser1047 are phosphorylated by CaM kinase II; mutation of either of these serines results in upregulated EGFR tyrosine autophosphorylation.