ERBB2 and breast carcinoma: This is particularly impressive given the evidence that c-erbB-2 gene and protein abnormalities in breast cancer predict poor prognosis and resistance to tamoxifen therapy and chemotherapy regimens such as CMF (cyclophosphamide, methotrexate, 5-fluorouracil) [7,10] However, the amplification and overexpression of c-erbB-2 proto-oncogene has been described in approximately 25–30 % of breast carcinomas [11,12].