ERBB2 and neoplasm: Overall, despite the association between EMT, stem-like cells, and resistance to therapy reported in some experimental contexts, our findings that HER2/neu residual disease is enriched for cells with an EMT-like phenotype whereas Wnt1 residual disease is not, and that neither HER2/neu nor Wnt1 residual disease is enriched for primary tumor TICs, suggest that the properties of TICs, mammary stem cells, and EMT are separable, at least in some contexts.