1. Pediatrics and Pediatric Surgery Department, Dr. Luis Calvo Mackenna Hospital, Faculty of Medicine, Universidad de Chile, Santiago, Chile
2. Oncology Unit, Dr. Luis Calvo Mackenna Hospital, Santiago, Chile
3. Hematopoietic Transplant Unit, Dr. Luis Calvo Mackenna Hospital, Santiago, Chile
4. Research and Epidemiology Unit, Medical School, Universidad Finis Terrae, Santiago, Chile