1. Department of Dermatology Stanford University School of Medicine Redwood City CA 94063 U.S.A
2. Department of Medicine Stanford Prevention Research Center Stanford University School of Medicine Redwood City CA 94063 U.S.A.
3. Department of Medicine Division of Oncology Stanford University School of Medicine Redwood City CA 94063 U.S.A.
4. Department of Health Research & Policy Division of Epidemiology Stanford University School of Medicine Redwood City CA 94063 U.S.A.
5. College of Medicine and Comprehensive Cancer Center Ohio State University Columbus OH U.S.A.
6. Department of Epidemiology Fairbanks School of Public Health Indiana University Indianapolis IN 46202 U.S.A.
7. Indiana University Melvin and Bren Simon Cancer Center Indianapolis IN 46202 U.S.A.