EPCAM and ovarian cancer: It is intriguing to note that in an in vivo mouse ovarian cancer model, a treatment with platinum agents caused significant tumor shrinkage; in contrast, a substantial enrichment of EpCAM-positive ovarian cancer cells was also observed, demonstrating that the remaining subpopulation of EpCAM-positive cancer stem cells is intimately associated with tumor relapse after chemotherapy [48] (Figure 2).