1. Department of Public Health, Faculty of Medicine, Semmelweis University, 1089 Budapest, Hungary
2. Department of Haematology and Stem Cell Transplantation, National Institute for Haematology and Infectious Diseases, South Pest Central Hospital, 1097 Budapest, Hungary
3. Department of Neurosurgery, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
4. Department of Health Promotion Sciences, College of Public Health, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
5. Peggy and Charles Stephenson Oklahoma Cancer Center, Oklahoma City, OK 73104, USA
6. Department of Pulmonology, Semmelweis University, 1083 Budapest, Hungary