Department of Bioengineering, Stanford, CA, USA.|Department of Bioengineering, Stanford, CA, USA.|Department of Clinical Pharmacology, South San Francisco, CA, USA.|Department of Safety Assessment, South San Francisco, CA, USA.|Biochemical and Cellular Pharmacology, South San Francisco, CA, USA.|Department of Drug Metabolism and Pharmacokinetic, Genentech Inc., South San Francisco, CA, USA.|Department of Safety Assessment, South San Francisco, CA, USA.|Department of Clinical Pharmacology, South San Francisco, CA, USA.|Department of Bioengineering, Stanford, CA, USA.