1. J. P. Sheridan, S. A. Marsters, R. M. Pitti, M. Skubatch, A. Ashkenazi, Department of Molecular Oncology, Genentech, South San Francisco, CA 94080–4918, USA.
2. A. Gurney, D. Baldwin, L. Ramakrishnan, C. L. Gray, K. Baker, W. I. Wood, A. D. Goddard, P. Godowski, Department of Molecular Biology, Genentech, South San Francisco, CA 94080–4918, USA.