Erythropoietin increases circulating endothelial progenitor cells and reduces the formation and progression of cerebral aneurysm in rats

▶Cerebral aneurysm (CA) induction decreases endothelial progenitor cells (EPCs). ▶EPO treatment mobilizes the circulating EPCs. ▶EPO treatment suppresses cerebral aneurysm formation and progression. ▶Circulating EPCs may be closely related to CA formation and progression. ▶EPO is a promising candidate of a novel preventive agent against CA.