1. National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892.
2. National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892.
3. Clinical Center, National Institutes of Health, Bethesda, MD 20892.
4. SAIC-Frederick, Cancer Research and Development Center, Frederick, MD 21702.