Indeed, a Canadian RCT trial conducted in 2013 in HSCT recipients, comparing an Hb threshold of 7 versus 12 g/dL, was stopped early due to the occurrence of severe veno-occlusive disease (VOD) in all patients enrolled in the 12 g/dL Hb threshold arm [34]. The gene discussed is GSTM1; the disease is hepatic veno-occlusive disease.