1. Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI 48109
2. Computer Science and Engineering Department, Michigan State University, East Lansing, MI 48824, USA
3. School of Computer Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
4. Department of Biological Chemistry, University of Michigan, Ann Arbor, MI 48109, USA