Program in Bioinformatics and Systems Biology, Sanford-Burnham Medical Research Institute, 92037 La Jolla, CA, USA. adam@godziklab.org.|Program in Bioinformatics and Systems Biology, Sanford-Burnham Medical Research Institute, 92037 La Jolla, CA, USA. adam@godziklab.org.|Program in Bioinformatics and Systems Biology, Sanford-Burnham Medical Research Institute, 92037 La Jolla, CA, USA. adam@godziklab.org.|Department of Computer Science, Hong Kong Baptist University, Kowloon Tong, Hong Kong. chxw@comp.hkbu.edu.hk.