1. Department of Biomedical Informatics, Harvard Medical School, Boston, Massachusetts 02115, United States
2. Department of Statistics, Harvard University, Cambridge, Massachusetts 02138, United States
3. Department of Information Engineering, Kun Shan University, Tainan City 710-03, Taiwan
4. Department of Computer Science and Information Engineering, National Cheng Kung University, Tainan City 701-01, Taiwan
5. Institute of Chemistry, Academia Sinica, Taipei 115-29, Taiwan
6. Department of Computer Science, Stanford University, Stanford, California 94305, United States
7. Department of Genetics, Stanford University, Stanford, California 94305, United States