1. Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA;
2. Norris Comprehensive Cancer Center/Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, USA;
3. Center for Ecogenetics and Environmental Health, Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, USA;
4. Department of Epidemiology and Biostatistics, School of Medicine, University of California, San Francisco, San Francisco, California, USA;
5. Department of Epidemiology, School of Public Health and Community Medicine, University of Washington, Seattle, Washington, USA