1. 1Department of Health Sciences, University of Florence, Florence, Italy
2. 2Hematology and Oncology Unit, Meyer Children’s Hospital Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Florence, Italy
3. 3Department of Medical Sciences, University of Turin, Turin, Italy
4. 4Nephrology and Dialysis Unit, Meyer Children’s Hospital IRCCS, Florence, Italy
5. 5Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
6. 6Department of Medical Oncology, All India Institute of Medical Sciences, New Delhi, India
7. 7Department of Pathology, All India Institute of Medical Sciences, New Delhi, India
8. 8Department of Pediatrics, Memorial Sloan Kettering Cancer Center, New York, NY
9. 9Department of Hemato-Oncology, Princess Máxima Center for Pediatric Oncology, Utrecht, The Netherlands
10. 10Department of Pediatrics, Mersin University Faculty of Medicine, Mersin, Turkey
11. 11Department of Dermatology, No. 1 Hospital of China Medical University, Shenyang, China
12. 12Department of Pediatric Hematology-Oncology, Istanbul University Cerrahpasa, Cerrahpasa Faculty of Medicine, Istanbul, Turkey
13. 13Department of Neurosurgery, Meyer Children’s Hospital IRCCS, Florence, Italy
14. 14NEUROFARBA Department, University of Florence, Florence, Italy
15. 15Department of Oncology, Azienda Ospedaliera di Rilievo Nazionale Santobono-Pausilipon, Pausilipon Hospital, Naples, Italy
16. 16Department of Pediatric Hematology/Oncology, Cellular and Gene Therapy, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
17. 17Pathology Unit, Meyer Children’s Hospital IRCCS, Florence, Italy
18. 18Department of Biomedical, Experimental and Clinical Sciences "Mario Serio," University of Florence, Florence, Italy
19. 19Cincinnati Children’s Hospital Medical Center, University of Cincinnati School of Medicine, Cincinnati, OH
20. 20Pediatric Oncology and Hematology, Armand-Trousseau Hospital, Assistance Publique-Hôpitaux de Paris, EA4340-BECCOH, Referral Center for Histiocytoses Université de Versailles Saint-Quentin-en-Yvelines, Paris, France
21. 21Department of Neurology, Memorial Sloan Kettering Cancer Center, New York, NY
22. 22EA4340 BECCOH, Université de Versailles Saint-Quentin-en-Yvelines, Service de Pathologie, Hôpital Ambroise Paré, Assistance Publique–Hôpitaux de Paris, Boulogne, France
23. 23Department of Internal Medicine, Institut E3M French Reference Centre for Histiocytosis, Pitié-Salpȇtrière Hospital, Assistance Publique-Hôpitaux de Paris, Sorbonne Université, Paris, France