GSTM1 and anemia (phenotype): In case of CKD patients with anemia, who are not treated with ESA, Hb levels should be measured when clinically indicated (Not Graded)—at least every 3 months in patients with CKD stage 3–5 who are not on dialysis (CKD-ND) or stage 5D on PD and every month in patients with CKD 5D in HD.