ERBB2 and breast cancer: To verify whether the EGFR and Her2/neu expression pattern in the tumors reflected those in the cell lines used for xenografts assays, total cell lysates were prepared from MCF10DCIS.com, MCF10DCIS.com-CK5high and MDA-MB-231 (positive control) breast cancer cells and analyzed for Her2/neu and EGFR protein expression by immunoblotting with the EGFR and Her2/neu antibodies used for immunohistochemical staining.