GSTM1 and cancer: In the European observational study ‘Current Practice of Aranesp in the Management of Hemoglobin Levels: an Observational International Cancer Evaluation’ (CHOICE), conducted in 11 European countries in 1900 patients with solid tumors, 57% of enrolled patients had a baseline Hb level <10 g/dL and 91% had <11 g/dL.