Abstract： @@ The manuscript by Xu et al1 addresses an important question in the field of allogeneic hematopoietic progenitor cell transplantation (HPCT): how to identify those patients at risk for hemmoraghic cystitis. The authors performed a retrospective analysis of 250 patients undergoing allogeneic HPCT following myeloablative conditioning with busulfan and cyclophosphamide using a standard post-transplant immunoprophylaxis with cyclosporine, short-course methotrexate and mycophenylate.