1. 1Division of Stem Cell Regulation, Center for Molecular Medicine, Jichi Medical University, Tochigi, Japan
2. 2Department of Hematology, Tokyo-Kita Medical Center, Tokyo, Japan
3. 3International Myeloma Center for Advanced Research and Treatment, Japan Association for Development of Community Medicine, Tokyo, Japan
4. 4Department of Hematology, Nephrology and Rheumatology, Akita University Graduate School of Medicine, Akita, Japan
5. 5Department of Hematology, National Hospital Organization Hiroshimanishi Medical Center, Hiroshima, Japan
6. 6Department of Hematology, Japanese Red Cross Society Suwa Hospital, Nagano, Japan
7. 7Institute of Immunology, Oslo University Hospital, Oslo, Norway
8. 8Department of Hematology/Oncology, The Institute of Medical Science, University of Tokyo, Tokyo, Japan