Computational Systems Biology Lab, Department of Biochemistry and Molecular Biology, and Institute of Bioinformatics, University of Georgia, Athens, USA. xizeng.mao@gmail.com.|Computational Systems Biology Lab, Department of Biochemistry and Molecular Biology, and Institute of Bioinformatics, University of Georgia, Athens, USA. qin.ma@sdstate.edu.|School of Mathematics, Shandong University, Jinan, Shandong, China. bingqiangsdu@gmail.com.|Computational Systems Biology Lab, Department of Biochemistry and Molecular Biology, and Institute of Bioinformatics, University of Georgia, Athens, USA. chenxin@uga.edu.|Computational Systems Biology Lab, Department of Biochemistry and Molecular Biology, and Institute of Bioinformatics, University of Georgia, Athens, USA. jluzhhy@gmail.com.|Computational Systems Biology Lab, Department of Biochemistry and Molecular Biology, and Institute of Bioinformatics, University of Georgia, Athens, USA. xyn@bmb.uga.edu.