Wei-Yi Ong1, Grace Y Sun2, W Gibson Wood3, Teng-Nan Lin4. 1. Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 119260, Singapore. 2. Department of Biochemistry, University of Missouri, Columbia, MO, USA. sung@missouri.edu. 3. Department of Pharmacology, University of Minnesota School of Medicine, Geriatric Research, Education and Clinical Center, VA Medical Center, Minneapolis, MN, USA. 4. Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan, ROC.