Department of Bioinformatics, University of Duisburg-Essen, Essen, Germany.|Department of Bioinformatics, University of Duisburg-Essen, Essen, Germany.|Department of Bioinformatics, University of Duisburg-Essen, Essen, Germany.|Department of Bioinformatics, University of Duisburg-Essen, Essen, Germany.