1. Bruker Daltonik GmbH, Fahrenheitstrasse 4, 28359 Bremen, Germany, Department of Biology and Center for Integrated Protein Science, Ludwig Maximilians University Munich, Grosshaderner Strasse 2, 82152 Planegg-Martinsried, Germany, Medizinisches Proteom-Center, Ruhr-Universitaet Bochum, Universitaetsstrasse 150, 44780 Bochum, Germany, and Clinical & Cellular Proteomics, Medical Faculty and Center for Medical Biotechnology, Duisburg-Essen University, 45117 Essen, Germany