1. Swiss Institute for Experimental Cancer Research (ISREC), School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL) , 1015 Lausanne , Switzerland
2. Wellcome Centre of Cell Biology, School of Biological Sciences, University of Edinburgh , EH9 3BF Edinburgh , UK
3. Department of Biology, Technische Universität Darmstadt , 64287 Darmstadt , Germany