EGF and breast cancer: The human epidermal growth factor receptor-2 (HER-2) is a 185 kDa transmembrane oncoprotein belonging to the human epidermal growth factor family.5 Its tyrosine kinase activity alone plays important roles in cell proliferation, differentiation, migration, and survival.6,7 Originally, HER-2 was widely studied in breast cancer, and its overexpression is typically correlated with more aggressive activity and a worse prognosis.8,9 As a successful target for trastuzumab in treatment of breast cancer, HER-2 status in other solid tumors has also been analyzed as well.