EPO and Ureteral obstruction: Because REP cells transform to myofibroblasts in injured kidneys with loss of the Epo-production ability and DNA hyper-methylation of the Epo gene promoter6,7,30, the myofibroblastic property of Replic cells was investigated by a comparison to fibrotic kidneys of normal mice subjected to unilateral ureteral obstruction (UUO) for 14 days.