1. Laboratory of Immunobiology, Center for Cancer Research, National Cancer Institute at Frederick, Frederick, MD 21702, USA
2. Laboratory of Experimental Immunology, Center for Cancer Research, National Cancer Institute at Frederick, Frederick, MD 21702, USA
3. Experimental Immunology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
4. Comparative Medicine Branch, NIAID, & SoBran, Inc., Rockville, MD 20892 USA
5. Laboratory Animal Sciences Program, National Cancer Institute at Frederick, Frederick, MD 21702, USA
6. Mouse Cancer Genetics Program, Center for Cancer Research, National Cancer Institute at Frederick, Frederick, MD 21702, USA
7. Basic Research Laboratory, Center for Cancer Research, National Cancer Institute at Frederick, Frederick, MD 21702, USA