EPO and anemia (phenotype): RRF, the remaining function of kidneys among patients with ESRD [20], confers multiple benefits to patients under chronic dialysis, and these benefits include permitting a lower ultrafiltration volume, less intradialytic hypotension, a lower prevalence of anemia and a decelerated course of malnutrition and inflammation, lower erythropoietin resistance, and ventricular hypertrophy [21–23].