1. From Pittsburgh NMR Center for Biomedical Research, and Department of Biological Sciences (Y.L.W., Q.Y., D.F.E., L.L., T.K.H., F.-C.Y., C.H.), and Department of Biomedical Engineering (F.-C.Y.), Carnegie Mellon University, Pittsburgh, PA; Department of Epidemiology, University of Pittsburgh, PA (B.L.R.); and Department of Molecular Cell Biology, Vrije Universiteit Medical Center, Amsterdam, the Netherlands (N.v.R.).