1. From the Department of Laboratory Medicine and Pathology (M.Y.T., B.T.S.) and Division of Biostatistics (W.G.), University of Minnesota School of Public Health, Minneapolis, MN; Department of Biostatistics, University of Washington, Seattle, WA (R.L.M.); Health Diagnostic Laboratory, Inc, Richmond, VA (R.W., J.M., D.M.H.); and National Institutes of Health Molecular Disease Branch, National Heart, Lung, and Blood Institute, Bethesda, MD (A.T.R.).