1. Department of Molecular and Cellular Sport Medicine; Institute of Cardiovascular Research and Sport Medicine; German Sport University Cologne; Cologne Germany
2. Municipal Clinics of Cologne; Clinic for Children and Youth Medicine; Pediatric Oncology/Hematology; Childreńs Hospital Amsterdamer Straße; Cologne Germany
3. Institute of Medical Statistics; Informatics and Epidemiology (IMSIE); University of Cologne; Cologne Germany