While the National Kidney Foundation defines anemia as hemoglobin (Hb) <135g/L (13.5g/ dL) in men and <120g/L (12g/dL) in women [6], a recent updated guideline of the United Kingdom Renal Association recommends the assessment for causes and weighing therapeutic options when Hb decreases below 110g/L (11g/dL) [9]. This evidence concerns the gene GSTM1 and anemia.