However, unlike primary human basal-like breast cancers that have been reported to express EGFR protein, EGFR expression in cell-line derived xenograft tumors was only weakly expressed in HCC1806 and TUM177 xenografts and not expressed preferentially in tumors derived from other Basal or Mesenchymal cell lines despite its expression in these cultured cell lines (Additional files 6 and 7, and [10]). This evidence concerns the gene EGFR and breast cancer.