Institution: | 1. Department of Statistical Science, Cornell University, Ithaca, New York 14853, U.S.A.;2. Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, U.S.A.;3. Department of Biostatistics, The University of Texas School of Public Health, Houston, Texas 77030, U.S.A.;4. Department of Biostatistics and Epidemiology, University of Pennsylvania, Philadelphia, Philadelphia 19104, U.S.A.equally contributed. |