1. Department of Pediatric Hematology-Oncology, Istituto di Ricovero e Cura a Carattere Scientifico Bambino Gesù Children’s Hospital, Rome, Italy;
2. Department of Pediatrics, University of Pavia, Pavia, Italy;
3. Division of Pediatric Hematology and Oncology, Department of Pediatrics, University of Freiburg, Freiburg, Germany;
4. German Cancer Consortium, Heidelberg, Germany; and
5. German Cancer Research Center, Heidelberg, Germany