EGFR,also named as ERBB1,is a cell-surface receptor for members of the epidermal growth factor family (EGF-family) of extracellular protein ligands. Binding of the protein to a ligand induces receptor dimerization and tyrosine autophosphorylation and leads to cell proliferation. The gene resides on chromosome 7p12,encoding a 170 kDa membrane-associated glycoprotein. Recent studies have shown EGFR plays a critical role in cancer development and progression,including cell proliferation,apoptosis,angiogenesis,and metastatic spread. Mutations in this gene are associated with lung cancer.