The basal-like epithelial breast cancer cell lines MDA-MD-468 and BT-20 were used as model systems, which are characterized by the positive expression of E-cadherin, negativity for hormone-receptors, lack of HER-2 amplification and high levels of basal markers, including high expression of EGFR and P-cadherin. This evidence concerns the gene ERBB2 and breast cancer.