Kaplan-Meier analysis of severe anaemia failure in the RCT arms, stratified by enrolment Hb level, showed a higher risk of severe anaemia failure in the group that had mild anaemia at enrolment (Hb 8.0-11.0 g/dL), compared to those with no anaemia at enrolment (Hb >11.0 g/dL) (log rank P-value < 0.001; Figure 3). This evidence concerns the gene GSTM1 and anemia (phenotype).