1. Department of Computer Science and Engineering, University of California, Riverside, CA, USA
2. School of Mathematics, Shandong University, Jinan, Shandong, China
3. Department of Integrative Biology and Physiology, University of California, Los Angeles, CA, USA
4. Institute of Integrative Genome Biology, University of California, Riverside, CA, USA
5. MOE Key Lab of Bioinformatics and Bioinformatics Division, TNLIST/Department of Computer Science and Technology, Tsinghua University, Beijing, China