Among patients with ferritin < 100 ng/mL who also had Hb < 12 g/dL, only 27–44% were prescribed with iron supplementation within 3 months after Hb measurement [29], thus indicating that iron replacement therapy remains considerably underestimated and a suboptimal management of CKD anaemic patients seems to be common in the clinical practice [21,29]. Here, GSTM1 is linked to chronic kidney disease.