1. Human Biology Division, Fred Hutchinson Cancer Research Center, Seattle, Washington
2. Molecular and Cellular Biology Program, University of Washington, Seattle
3. Medical Scientist Training Program, University of Washington, Seattle
4. Department of Global Health, University of Washington, Seattle
5. Department of Epidemiology, University of Washington, Seattle
6. Department of Paediatrics and Child Health, University of Nairobi, Kenyatta National Hospital, Kenya
7. Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington