1. Unit of Virus, Lifestyle and Genes; Danish Cancer Society Research Center; Copenhagen Denmark
2. Department of Research; Cancer Registry of Norway; Oslo Norway
3. Icelandic Cancer Registry; Icelandic Cancer Society; Reykjavik Iceland
4. Faculty of Medicine; University of Iceland; Reykjavik Iceland
5. Epidemiology; Merck; Kenilworth New Jersey
6. Department of Laboratory Medicine; Karolinska Institute; Stockholm Sweden
7. Department of Obstetrics and Gynecology; Copenhagen University Hospital, Rigshospitalet; Copenhagen Denmark