Key Laboratory of Computational Biology, MPG-CAS PICB, Shanghai, PR China. christine@picb.ac.cn|Key Laboratory of Computational Biology, MPG-CAS PICB, Shanghai, PR China. christine@picb.ac.cn|Key Laboratory of Computational Biology, MPG-CAS PICB, Shanghai, PR China. christine@picb.ac.cn|Key Laboratory of Computational Biology, MPG-CAS PICB, Shanghai, PR China. christine@picb.ac.cn