1. Pathology/Histotechnology Laboratory, Science Applications International Corporation, National Cancer Institute/Frederick Cancer Research and Development Center, Frederick, MD
2. Laboratory Animal Sciences Program, Science Applications International Corporation, National Cancer Institute/Frederick Cancer Research and Development Center, Frederick, MD
3. Laboratory of Cell and Molecular Structure, Science Applications International Corporation, National Cancer Institute/Frederick Cancer Research and Development Center, Frederick, MD
4. Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, MA (JGF, NST, ZS)
5. Department of Molecular Genetics, Forsyth Dental Center, Boston, MA (FED)
6. Veterinary and Tumor Pathology Section, Animal Sciences Branch, Office of Laboratory Animal Resources, Division of Basic Sciences, National Cancer Institute, Frederick, MD (JMW)