GSTM1 and myelodysplastic syndrome: In the first, observational, part of this 2‐part study, we assessed the impact of transfusion dependence on overall survival (OS) and non‐leukemic death in untreated del(5q) MDS patients who were TD (n = 136), TI with hemoglobin (Hb) ≥10 mg/dL (n = 88), or TI with Hb <10 mg/dL (n = 96).