1. Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Hyogo 650‑0017, Japan
2. Department of Public Health, Kobe University Graduate School of Health Science, Kobe, Hyogo 654‑0142, Japan
3. Department of Hematology and Oncology, Kobe Children's Hospital, Kobe, Hyogo 650‑0047, Japan