1. Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA;
2. Department of Psychosocial Oncology and Palliative Care, Dana-Farber Cancer Institute, Boston, Massachusetts, USA;
3. Hematology/Oncology/Blood & Marrow Transplant Program, Alberta Children’s Hospital, Calgary, Alberta, Canada