1. Division of Molecular Genetic Epidemiology; German Cancer Research Center (DKFZ), Im Neuenheimer Feld 580; Heidelberg D-69120 Germany
2. Center for Primary Health Care Research, Lund University; Malmö 205 02 Sweden
3. Stanford Prevention Research Center, Stanford University School of Medicine, 94305-5705; Stanford California USA
4. Cancer Gene Therapy Group, Faculty of Medicine, University of Helsinki; Finland
5. Helsinki University Hospital Comprehensive Cancer Center; Helsinki Finland