1. Pediatric Hematology and Oncology Unit ARNAS "Civico, Di Cristina and Benfratelli" Hospitals Palermo Italy
2. Pediatric Hematology and Oncology Department Ospedale Pediatrico Bambino Gesù IRCCS Rome Italy
3. Unit of Clinical Epidemiology and Trial Organization Fondazione IRCCS Istituto Nazionale dei Tumori di Milan Milan Italy
4. Hematology/Oncology Division Department of Women's and Children's Health University of Padua Padua Italy
5. Department of Hematology and Oncology Istituto G. Gaslini Genoa Italy
6. Pediatric Surgery Division Department of Women's and Children's Health University of Padua Padua Italy
7. Pediatric Hematology and Oncology Unit Catania University Catania Italy
8. Pediatric Surgery Unit Ospedale Pediatrico Bambino Gesù Rome Italy
9. Pediatric Hematology and Oncology Unit Papa Giovanni XXIII Hospital Bergamo Italy
10. Pediatric Oncology Unit Santobono‐Pausilipon Hospitals Naples Italy
11. Department of Pediatric Surgery “Buzzi” Children Hospital Milan Italy
12. Pediatric Oncology Unit Fondazione IRCCS Istituto Nazionale Tumori Milan Italy