This is because it is possible that patients may have felt better knowing they were receiving the study drug, which could partially explain any improvements in PROs observed in Part B. However, improvements were also observed in more objective measures of disease activity (published in a separate manuscript) including improvements in Hb and bilirubin levels, which are markers of anaemia and haemolysis, respectively. The gene discussed is GSTM1; the disease is anemia (phenotype).