1. Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA.
2. Laboratory of Virology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT 59840, USA.
3. Basic Sciences Division and Computational Biology Program, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.
4. Department of Genome Sciences and Medical Scientist Training Program, University of Washington, Seattle, WA 98195, USA.
5. BIOQUAL, Rockville, MD, USA.
6. MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DS, UK.
7. Chinese Academy of Medical Sciences, Oxford Institute, University of Oxford, Oxford OX3 9DS, UK.
8. Howard Hughes Medical Institute, Seattle, WA 98109, USA.