Department of Computer Science and Engineering, Jacobs School of Engineering, University of California, 9500 Gilman Drive, La Jolla, San Diego, 92093, USA.|Department of Computer Science and Engineering, Jacobs School of Engineering, University of California, 9500 Gilman Drive, La Jolla, San Diego, 92093, USA.|Department of Biomedical Informatics, School of Medicine, University of California, 9500 Gilman Drive, La Jolla, San Diego, 92093, USA.|Department of Computer Science and Engineering, Jacobs School of Engineering, University of California, 9500 Gilman Drive, La Jolla, San Diego, 92093, USA.|Department of Computer Science and Engineering, Jacobs School of Engineering, University of California, 9500 Gilman Drive, La Jolla, San Diego, 92093, USA.|Department of Biomedical Informatics, School of Medicine, University of California, 9500 Gilman Drive, La Jolla, San Diego, 92093, USA. chunnan@ucsd.edu.