GSTM1 and hemoglobinopathy: Existing hemoglobinopathy screening tests, including high-performance liquid chromatography (HPLC), isoelectric focusing electrophoresis (IEF) and capillary zone electrophoresis (CZE) [6, 7] are based on the structural integrity of Hb, which are easily affected by sample hemolysis or Hb degradation [8].