Recent evidence shows that spheroid formation and prostate cancer stem cells are linked to E-cadherin expression and epithelial-mesenchymal transition.22, 23 Since knockdown of PRH in normal PNT2-C2 cells also results in decreased E-cadherin expression, as well as increased spheroid formation, we conclude that PRH normally regulates self-renewal, cell proliferation and cell-cell contacts in these cells. This evidence concerns the gene CDH1 and Familial prostate cancer.