1. Department of Haematology/Oncology; Gunma Children's Medical Centre; Shibukawa Japan
2. Department of Paediatrics; Gunma University Graduate School of Medicine; Maebashi Japan
3. Department of Pathology and Tumour Biology; Graduate School of Medicine; Kyoto University; Kyoto Japan
4. Laboratory of DNA Information Analysis; Human Genome Centre; Institute of Medical Science; The University of Tokyo; Tokyo Japan
5. Department of Paediatrics; Nagoya University Graduate School of Medicine; Nagoya Japan
6. Laboratory of Sequence Analysis; Human Genome Centre; Institute of Medical Science; The University of Tokyo; Tokyo Japan
7. Department of Paediatrics; Hirosaki University Graduate School of Medicine; Hirosaki Japan
8. Department of Paediatrics Haematology and Oncology Research; National Centre for Child Health and Development; Tokyo Japan
9. Department of Paediatrics; Okayama University Graduate School of Medicine; Okayama Japan
10. Department of Paediatrics; The University of Tokyo; Tokyo Japan
11. Division of Leukaemia and Lymphoma; Children's Cancer Centre; National Centre for Child Health and Development; Tokyo Japan
12. Department of Paediatrics; Fujita Health University School of Medicine; Toyoake Japan
13. Human Health Sciences; Kyoto University Graduate School of Medicine; Kyoto Japan
14. Department of Paediatrics; Shiga University of Medical Science; Ohtsu Japan
15. Department of Paediatrics; National Hospital Organization Osaka National Hospital; Osaka Japan
16. Clinical Research Centre; National Hospital Organization Nagoya Medical Centre; Nagoya Japan
17. Japanese Red Cross Gunma Blood Centre; Maebashi Japan