1. Department of Biochemistry and Molecular Biology (E.S., C.-Y.L., S.J., J.L., B.R.Z., H.C.), Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland 21205
2. Population Council (C.M.S., R.G.), New York, New York 10065
3. The Second Affiliated Hospital (R.G., H.C.), Wenzhou Medical College, Wenzhou, Zhejiang 325000, PR China