1. Joseph G. Ibrahim is Alumni Distinguished Professor and Hongtu Zhu is Associate Professor , Department of Biostatistics, University of North Carolina, Chapel Hill. Niansheng Tang is Professor, Department of Statistics, Yunnan University, Kunming . The authors wish to deeply thank the editor, the associate editor, and three referees for extremely helpful comments and suggestions that have substantially improved the article. Dr. Ibrahim’s research was supported in part by National Institutes of Health...