1. Department of Cellular and Molecular Pharmacology, Box 0450, and Department of Hematology/Oncology, Cancer Research Institute, Box 0128, University of California, San Francisco, San Francisco, California 94143, Sequus Pharmaceuticals, Inc., 1050 Hamilton Court, Menlo Park, California 94025, and Genentech, Inc., 460 Point San Bruno Boulevard, South San Francisco, California 94080