NARECHEM-ST has been fostered since initiation (1996) in the Department of Hygiene Epidemiology and Medical Statistics, Medical School, National and Kapodistrian University of Athens Greece; specific access is granted only after signature of binding documents to health personnel needed to work with raw data. The Principal Investigator Prof E. Petridou, the Co-Principal Investigator Associate Prof. E. Ntzani and the Data Managers all provide their contributions for gratis. Statistical support has been provided until 2019 by the University of Athens and thereafter on ad hoc basis by the University of Ioannina, whereas the Society for Social Pediatrics and Health Promotion and contribute administrative, technical support and data collection/cleaning personnel. A network of childhood cancer specialists comprising hematologists-oncologists, surgeons, neurosurgeons, pathologists, neurologists, radiologists and radiotherapists, geneticists as well bone marrow transplantation therapists is contributing data and scientific expertise. Collected data are being scientifically exploited by undergraduate and graduate university students under appropriate academic supervision of the NARECHEM-ST yielding a long series of publications and Doctoral Theses.