1. N. Balaban, R. T. Nhan, S. Scott, R. M. Ridgley, R. Rasooly, J. R. Carlson, Department of Medical Pathology, University of California, Davis, CA 95616, USA.
2. T. Goldkorn and L. B. Dang, Department of Internal Medicine, University of California, Davis Medical Center, Davis, CA 95616, USA.
3. A. Rasooly, Department of Microbiology, University of Maryland, College Park, MD 20742, USA.
4. S. C. Wright and J. W. Larrick, Palo Alto Research Institute of Molecular Medicine, Mountain View, CA 94043, USA.