1. Neonatology Department; Hospital General Universitario Gregorio Marañón; Madrid Spain
2. Pediatric Surgery Department; Hospital General Universitario Gregorio Marañón; Madrid Spain
3. Pediatric Oncology Department; Hospital General Universitario Gregorio Marañón; Madrid Spain
4. Pathology Department; Hospital General Universitario Gregorio Marañón; Madrid Spain
5. Medical and Translational Research Department; European Organisation for Research and Treatment of Cancer (EORTC); Brussels Belgium