GSTM1 and hemorrhagic cystitis: Table 3 shows pre-transfusion Hb levels, and the number of RBC transfusions administered during the first 100 days after transplantation for the entire study population and for two subgroups of patients, those without hemorrhagic transplant complications and those who developed hemorrhagic transplant complications (i.e., severe hemorrhagic cystitis due to Polyomavirus BK or Adenovirus infection, severe acute gastrointestinal GVHD, severe gastrointestinal thrombotic mycroangiopathy).