EPCAM and breast cancer: Our findings established that epithelial and mesenchymal subpopulations, defined by their EpCAM expression, exist within the PMC42-LA breast cancer cell line, which maintains on average an EpCAM+/High epithelial and EpCAMLow mesenchymal population ratio of 80:20; whereas, the panel of other luminal cell lines (MCF7, T47D) and basal cell lines (MDA-MB-231, Sum159, HCC38), FACS profiled using EpCAM, displayed a uniform distribution of EpCAM high and EpCAM low states.