1. Department of Hematology Imamura Bun‐in Hospital KagoshimaJapan
2. Department of Hematology National Kyushu Cancer Center FukuokaJapan
3. Division of Epidemiology and Prevention Aichi Cancer Center Research Institute NagoyaJapan
4. Department of Pathology Kurume University School of Medicine KurumeJapan
5. Department of Pharmaceutical Development Immuno‐Biological Laboratories Fujioka Japan