1. Department of Physiological Chemistry, Genentech, 1 DNA Way, South San Francisco, CA 94080, USA.
2. Department of Early Discovery Biochemistry, Genentech, 1 DNA Way, South San Francisco, CA 94080, USA.
3. Department of Pathology, Genentech, 1 DNA Way, South San Francisco, CA 94080, USA.
4. Department of Molecular Biology, Genentech, 1 DNA Way, South San Francisco, CA 94080, USA.