Research Group Theoretical Systems Biology, Department of Bioinformatics, Friedrich-Schiller-Universität Jena, Jena, Germany.|Research Group Theoretical Systems Biology, Department of Bioinformatics, Friedrich-Schiller-Universität Jena, Jena, Germany.|Department of Bioinformatics, Biocenter, Julius-Maximilians-Universität Würzburg, Würzburg, Germany.|Research Group Medical Systems Biology, Christian-Albrechts-Universität zu Kiel, Kiel, Germany.