1. Medical Scientist Training Program, University of Washington, Seattle, Washington 98105.
2. Molecular and Cellular Biology Program, University of Washington, Seattle, Washington 98105.
3. Vaccine and Infectious Disease Institute, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109.
4. Department of Medicine, University of Washington School of Medicine, Seattle, Washington 98105.
5. Department of Laboratory Medicine, University of Washington School of Medicine, Seattle, Washington 98105.