1. Department of Pediatrics St. Marianna University School of Medicine Kanagawa Japan
2. Children's Cancer Center, National Center for Child Health and Development Tokyo Japan
3. Clinical Research Center, NHO Nagoya Medical Center Aichi Japan
4. Department of Pediatric Hematology and Oncology Research National Research Institute for Child Health and Development Tokyo Japan
5. Department of Pediatrics Graduate School of Medical Sciences Kyushu University Fukuoka Japan
6. Department of Pediatrics Yamaguchi University Graduate School of Medicine Yamaguchi Japan
7. Department of Pediatrics Hiroshima Red Cross Hospital and Atomic‐bomb Survivors Hospital Hiroshima Japan
8. Department of Pediatrics Yamagata University Yamagata Japan
9. Department of Hematology and Oncology Children's Cancer Center, Hyogo Prefectural Kobe Children's Hospital Hyogo Japan
10. Department of Clinical Research Saitama Children's Medical Center Saitama Japan
11. Department of Hematology/Oncology for Children and Adolescents Sapporo Hokuyu Hospital Hokkaido Japan
12. Department of Pediatrics NHO Nagoya Medical Center Aichi Japan