1 Pediatric Oncology Unit, Fondazione Policlinico Universitario Agostino Gemelli Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Università Cattolica del Sacro Cuore, Rome, Italy.
2 Department of Paediatric and Adolescent Haematology/Oncology, Great North Children's Hospital, Newcastle, United Kingdom.
3 Newcastle University Centre for Cancer, University of Newcastle, Newcastle, United Kingdom.
4 National Cancer Institute, Cairo University and Children Cancer Hospital, Cairo, Egypt.