[1] Gunma Childrens Med Ctr, Dept Hematol Oncol, Gunma, Japan
[2] Japan Childrens Canc Grp, Tokyo, Japan
[3] Yokohama City Univ Med, Dept Pediat, Yokohama, Kanagawa, Japan
[4] Kyoto Univ, Dept Pathol & Tumor Biol, Grad Sch Med, Kyoto, Japan
[5] Kyoto Univ, Grad Sch Med, Human Hlth Sci, Kyoto, Japan
[6] Natl Ctr Child Hlth & Dev, Div Leukemia & Lymphoma, Childrens Canc Ctr, Tokyo, Japan
[7] Shiga Univ Med Sci, Dept Pediat, Shiga, Japan
[8] Jobu Univ, Inst Physiol & Med, Gunma, Japan