Florian Kreppel1, Anja Ehrhardt2. 1. Chair for Biochemistry and Molecular Medicine, Center for Biomedical Education and Research (ZBAF), Department of Human Medicine, Faculty of Health, University Witten/Herdecke, Witten, Germany. florian.kreppel@uni-wh.de. 2. Chair for Virology and Microbiology, Center for Biomedical Education and Research (ZBAF), Department of Human Medicine, Faculty of Health, University Witten/Herdecke, Witten, Germany. anja.ehrhardt@uni-wh.de.