ERBB2 and neoplasm: Residual tumor cells in each of these models were also enriched for phenotypes reported to be associated with TICs—EMT, in the case of HER2/neu, and a CD24+Thy1+ cell surface phenotype, in the case of Wnt1. Despite these suggestive phenotypic traits, functional studies revealed that residual tumor cells were not enriched for primary tumor TICs.