1. Laboratory of Molecular Oncology, National Cancer Institute, National Institutes of Health, Frederick, MD 21701-1013.
2. Laboratory of Tumor Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892.
3. Program Resources, Inc., Frederick Cancer Research Facility, Frederick, MD 21701-1013.
4. Virus Control Unit, National Cancer Institute, National Institutes of Health, Frederick, MD 21701-1013.