1. Faculty of Chemistry and Pharmacy, Institute of Pharmacy, University of Regensburg, D-93040 Regensburg, Germany, Research Unit Molecular Cell Biology, Medical Faculty, Friedrich Schiller University, D-07747 Jena, Germany, Oncotest GmbH, Am Flughafen 12-14, D-79108 Freiburg, Germany, ASTA Medica AG, Department of Cancer Research, D-60314 Frankfurt/Main, Germany