1. Division of Medical Oncology and Hematology Department of Medicine Kobe University Hospital Kobe Japan
2. Division of Cardiovascular Medicine Department of Internal Medicine Kobe University Graduate School of Medicine Kobe Japan
3. Jerome Lipper Multiple Myeloma Center Department of Medical Oncology Dana‐Farber Cancer Institute Harvard Medical School Boston Massachusetts USA
4. BioResource Center Kobe University Hospital Kobe Japan
5. Laboratory of Hematology Division of Medical Biophysics Kobe University Graduate School of Health Sciences Kobe Japan