Karkouti K, et al. - In patients who underwent cardiac surgery, researchers examined the links between pre-operative anaemia (haemoglobin < 130 g.l^-1 in men and < 120 g.l^-1 in women), intra-operative hepcidin concentration and acute kidney injury (dialysis or > 26.4 μmol.l^-1 or > 50% creatinine increase during the first two days after cardiac surgery. They found that in these subjects, the Cleveland risk score-predicted rate of postoperative acute kidney injury might be adjusted for pre-operative anaemia and intra-operative cardiopulmonary bypass time and hepcidin concentration. They observed that acute kidney injury might be attenuated by pre-operative correction of anaemia, reduction in intra-operative bypass time and modification of iron homeostasis and hepcidin concentration.