GSTM1 and anemia (phenotype): The mean Hb was similar in patients treated in units in Portugal (11.0 (1.3) g/dL) and in Poland (11.0 (1.3) g/dL) and the proportion of patients within the recommended KDIGO anemia target of Hb 10–12 g/dL was also similar (66 and 70% respectively, Table 1, Table 2 and Fig. 1).