EPO and anemia (phenotype): The aging process may further affect hematopoiesis by altering the production of hematopoietic ILs and decreasing the production of erythropoietin (EPO) in the kidneys as well as increasing the oxidative damage to erythrocyte membranes, which in turn may lead to anemia of a variety of etiologies (Kedziora-Kornatowska, 2005).