1. From the Division of Molecular Medicine, Department of Medicine (M. Wang, M.S., S.A., A.J.M., C.W., I.T., M. Westerterp, A.R.T.) and Department of Pharmacology (M. Wang), Columbia University, New York, NY; Department of Medicine, University of California San Diego, La Jolla (A.G., J.W.); and Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands (M. Westerterp).