1. Donald W. Reynolds Cardiovascular Clinical Research Center and Department of Internal Medicine (S.G.L., F.X., G.L.V., S.M.G., M.C., J.C.C., H.H.H.), University of Texas Southwestern Medical Center, Dallas, Texas 75390-9046
2. Merck and Co., Inc. (C.L., R.S.L., M.E.S., T.A.M.), North Wales, Pennsylvania 19454
3. Department of Molecular Genetics and Howard Hughes Medical Institute (H.H.H.), University of Texas Southwestern Medical Center, Dallas, Texas 75390-9046