1. Institute of Structural Biology, University of Bonn, Venusberg-Campus 1, 53127 Bonn, Germany
2. Max Planck Institute for Multidisciplinary Sciences, Bioanalytical Mass Spectrometry, 37077 Göttingen, Germany
3. Hematology/Oncology, Department of Medicine II, Johann Wolfgang Goethe University, 60590 Frankfurt am Main, Germany
4. Frankfurt Cancer Institute, Goethe University, 60596 Frankfurt am Main, Germany
5. Institute of Clinical Chemistry, Bioanalytics Group, University Medical Center Göttingen, Göttingen, Germany