1. Quantitative and Computational Biology Program, University of Southern California, Los Angeles, CA 90089, USA
2. Biology Department, Clark University, Worcester, MA 01610, USA
3. Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
4. Inflammatory Bowel and Immunobiology Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA