1. University of California, San Francisco
2. University of Washington, Seattle
3. Group Health Research Institute, Seattle, Washington
4. Blood Systems Research Institute, San Francisco, California
5. Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
6. University of California, San Diego
7. Aaron Diamond AIDS Research Center, New York, New York
8. McGill University Health Center, Montreal, Quebec, Canada
9. Fred Hutchinson Cancer Research Center, Seattle, Washington