1. From the Center for Molecular Therapeutics (M.R.R., I.S.C., R.B.R.) and Departments of Pharmacology (M.R.R., I.S.C., R.B.R.) and Pediatrics (M.R.R.), College of Physicians and Surgeons of Columbia University, New York, NY; and Institute for Molecular Cardiology (M.R.R., P.R.B., I.S.C.) and Department of Physiology and Biophysics (M.R.R., P.R.B., I.S.C.), Stony Brook University, Stony Brook, NY.