Department of Computer Science, City University of Hong Kong, Kowloon, Hong Kong, Department of BioHealth Informatics, Indiana University-Purdue University Indianapolis and Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, IN 46202, USA.|Department of Computer Science, City University of Hong Kong, Kowloon, Hong Kong, Department of BioHealth Informatics, Indiana University-Purdue University Indianapolis and Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, IN 46202, USA.|Department of Computer Science, City University of Hong Kong, Kowloon, Hong Kong, Department of BioHealth Informatics, Indiana University-Purdue University Indianapolis and Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, IN 46202, USA Department of Computer Science, City University of Hong Kong, Kowloon, Hong Kong, Department of BioHealth Informatics, Indiana University-Purdue University Indianapolis and Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, IN 46202, USA.