1. Department of Applied Tumor Biology, Institute of Pathology, University of Heidelberg and Clinical Cooperation Unit, German Cancer Research Center, Heidelberg, Germany
2. Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, MD
3. Department of Pathology, VU University Medical Center, Amsterdam, the Netherlands
4. Unit of Cancer Epidemiology, Scientific Institute of Public Health, Brussels, Belgium.