1. Department of Hematology, National Center for Global Health and Medicine, Tokyo, Japan
2. Division of Blood and Bone Marrow Transplantation, Department of Medicine, University of Louisville School of Medicine, Louisville, KY, USA
3. Department of Blood Transfusion and Transplantation Immunology, Fukushima Medical University School of Medicine, Fukushima, Japan
4. Department of Pathology, Kitasato University, School of Medicine, Sagamihara, Japan