1. Ruhrlandklinik, West German Lung Centre, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
2. Institute of Pathology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
3. Institute of Pathology, University Hospital Cologne, Köln, Germany
4. Institute of Pathology, Division of Molecular Pathology, Charité, Berlin, Germany
5. Department of Medical Oncology, West German Cancer Centre, University Hospital Essen, University of Duisburg-Essen, Essen, Germany