1. Department of Pathology, University of Hong Kong, Pokfulam, Hong Kong, People's Republic of China
2. Department of Pathology, Stanford University, Palo Alto, CA, U.S.A.
3. Department of Biochemistry, University of Science and Technology, Hong Kong, People's Republic of China
4. Department of Biochemistry, University of Hong Kong, Pokfulam, Hong Kong, People's Republic of China