1. Departments of Small Molecule Drug Discovery, Cell Cycle and Global Regulators, Translational Oncology, and Protein Engineering, Genentech, Inc., 1 DNA Way, South San Francisco, California 94080, and Departments of Medicinal Chemistry, Cell Biology, and HTS and Biochemistry, Pharma Research, Roche Diagnostics GmbH, D-82372 Penzberg, Germany