1. University of Kansas School of Medicine, Kansas City, Kansas.
2. Department of Pediatrics and Adolescent Medicine, Center of Adolescent Medicine, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.
3. Department of Hematology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.
4. Department of Pediatric Hematology and Oncology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.
5. Department of Pediatric and Adolescent Medicine, and Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.
6. Department of Oncology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.