Institute of Bioinformatics, Tsinghua University, Beijing 100084, Peoples Republic of China.|Institute of Bioinformatics, Tsinghua University, Beijing 100084, Peoples Republic of China.|Institute of Bioinformatics, Tsinghua University, Beijing 100084, Peoples Republic of China.|Institute of Bioinformatics, Tsinghua University, Beijing 100084, Peoples Republic of China.|Institute of Bioinformatics, Tsinghua University, Beijing 100084, Peoples Republic of China.