CMBI, Center for Molecular and Biomolecular Informatics, Toernooiveld 1, NL-6525 ED Nijmegen, The Netherlands. elmar.krieger@cmbi.kum.nl|CMBI, Center for Molecular and Biomolecular Informatics, Toernooiveld 1, NL-6525 ED Nijmegen, The Netherlands. elmar.krieger@cmbi.kum.nl