1. From the Departments of Cell Biology, The Scripps Research Institute (Miss Marrinucci and Miss Luttgen and Dr Kuhn), and Pathology, Scripps Clinic (Dr Bethel), La Jolla, California; the Department for Biotechnology, The Palo Alto Research Center, Palo Alto, California (Dr Bruce); and the Department of Oncology and Hematology, Billings Clinic, North, Billings, Montana (Dr Nieva).
2. Reprints: Peter Kuhn, PhD, The Scripps Research Institute, 10550 North Torrey Pines Rd, GAC-1200, La Jolla, CA 92037 (pkuhn@scripps.edu).