1. Department of Hematology, University of Tsukuba Hospital, Ibaraki, Japan
2. Department of Hematology, Faculty of Medicine, University of Tsukuba, Ibaraki, Japan
3. Department of Hematology, Tsuchiura Kyodo General Hospital, Ibaraki, Japan
4. Department of Pathology, National Hospital Organization Mito Medical Center, Ibaraki, Japan
5. Department of Hematology/Oncology, Institute of Medical Science, University of Tokyo, Tokyo, Japan
6. Department of Pathology and Tumor Biology, Kyoto University, Kyoto, Japan