1. Department of Epidemiology and Jonsson Comprehensive Cancer Center, University of California at Los Angeles, Los Angeles, California 90095.
2. Department of Epidemiology, Bloomberg School of Public Health, The Johns Hopkins University, Baltimore, Maryland 21205.
3. Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15213.
4. Department of Medicine, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, California 90095.
5. Departments of Obstetrics and Gynecology and Microbiology, Immunology and Molecular Genetics, David Geffen School of Medicine at UCLA, Los Angeles, California 90095.
6. Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, The Johns Hopkins University, Baltimore, Maryland 21205.
7. Department of Preventive Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611.