BACKGROUND AND AIM: Long term high-dose erythropoietin (EPO) had been reported inducing the formation of abdominal aortic aneurysm (AAA) in mice. When using this model, we found that EPO treated mice showed significant splenomegaly. This is an interesting phenomenon, and its mechanism has not been reported. Therefore, this study aims to explore its mechanism. METHODS: C57BL/6 mice were given intraperitoneal injection of recombinant human EPO at 10000 IU/kg/day, and the control mice were treated with normal saline (vehicle). After 3 weeks, the spleens were harvested. Pathological changes in his...