Intravenous iron sucrose 200 mg/wk for 6 weeks in patients with anemia (Hb < 12 g/dL) and cardiorenal syndrome increased Hb levels from 10.6 to 11.9 g/dL (p < 0.001), results that are similar to the combined treatment with epoetin-b (Hb from 10.2 to 12.4 g/dL; p < 0.001) studies, as suggested in [41]. Here, GSTM1 is linked to anemia (phenotype).