Consistent with our findings in the HER2/neu-Prim1 orthotopic model, uncultured orthotopic primary tumors derived from MTB;TetO-HER2/neu;TTC;rYFP mice were predominantly epithelial (CD24+EpCAM+CD49e−PDGFR-β−), whereas residual lesions were enriched for tumor cells with mesenchymal-like properties (CD24−EpCAM−CD49e+PDGFR−β+) (Fig. 7a–d). This evidence concerns the gene ERBB2 and neoplasm.