Anemia, defined as serum haemoglobin (Hb) levels ≤12 gm/dL in women and ≤13 gm/dL in men, is a common complication of chronic kidney disease (CKD), being prevalent twice as much in the affected adult population (15.4%) as opposed to the general population (7.4%). Here, GSTM1 is linked to anemia (phenotype).