In this report, we discovered that KDM2B, a member of variant PRC1 complex and also a histone H3 demethylase, epigenetically regulated the downregulation of several epithelial marker genes including CDH1, which was indispensable for TGF-β-induced EMT of lung and pancreatic cancer cells. The gene discussed is PRC1; the disease is familial pancreatic carcinoma.