Program in Molecular and Computational Biology, University of Southern California Los Angeles, CA 90089, USA.|Program in Molecular and Computational Biology, University of Southern California Los Angeles, CA 90089, USA.|Program in Molecular and Computational Biology, University of Southern California Los Angeles, CA 90089, USA.|Program in Molecular and Computational Biology, University of Southern California Los Angeles, CA 90089, USA.|Program in Molecular and Computational Biology, University of Southern California Los Angeles, CA 90089, USA.