EPO and anemia (phenotype): With regard to the concept of EPO resistance, according to the clinical practice guidelines for anemia caused by renal failure issued by the National Kidney Disease Foundation (NKF), after using rhEPO 400 IU/kg or 20,000 IU every week for three months, If the blood hemoglobin concentration of the patient is still less than 11g/dL, it can be diagnosed as rhEPO resistance (KDOQI and National Kidney Foundation, 2006).