On the other hand, the patient had advanced renal anemia, as evidenced by the normal serum concentration of erythropoietin (17.7 mIU/mL, reference of 9.1–32.8 mIU/mL) despite a severely reduced concentration of hemoglobin (7.6 g/dL, reference of 11.6–14.8 g/dL) when anemia was initially detected at the age of 78 years. Here, EPO is linked to anemia (phenotype).