1. Department of Quantitative and Computational Biology, University of Southern California , Los Angeles , CA 90089, USA
2. Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California , Los Angeles , CA 90089, USA
3. Norris Comprehensive Cancer Center, University of Southern California , Los Angeles , CA 90033, USA
4. Departments of Chemistry, Physics & Astronomy, and Computer Science, University of Southern California , Los Angeles , CA 90089, USA