GSTM1 and anemia (phenotype): In patients with non-dialysis-dependent CKD (estimated glomerular filtration rate [eGFR] ≤ 60 mL/min/1.73 m2) the FIND-CKD study showed that targeting a high ferritin level (400–600 μg/L) with intravenous iron was more successful in increasing Hb levels than oral iron and may contribute to improved overall anaemia management [25].