1. Department of Child Health and Development, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
2. Department of Pediatrics and Developmental Biology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
3. Department of Pediatrics, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
4. Division of Hematology, Hokkaido University Hospital, Sapporo, Japan