EPO and anemia (phenotype): The vast majority, if not all patients with renal anemia require maintenance replacement therapy with human recombinants erythropoietin stimulating agents (rESA) such as epoetin, which is a recombinant form of erythropoietin, a hematologic growth factor that induces proliferation and maturation of red blood cells and is used in the treatment of anemia caused by renal disease.3