1. University of California, San Francisco, California, 94143, and the End Results Section, National Cancer Institute, National Institutes of Health, Bethesda, Md., 20014.
2. Cancer Research Institute; Department of International Health; Department of Pathology, University of California, San Francisco, Calif 94143.
3. End Results Section, Biometry Branch, National Cancer Institute, Bethesda, Md. 20014.
4. M.D. Anderson Hospital and Tumor Institute, Houston, Texas; formerly at University of California, San Francisco, Calif 94143.
5. Cancer Research Institute, University of california, San Francisco, Calif 94143.