1. Department of Thoracic Surgery, Kliniken Essen-Mitte Evang. Huyssens-Stiftung/Knappschafts-Krankenhaus, Essen, Germany
2. Department of Thoracic Surgery, Helios University Hospital Wuppertal, Wuppertal, Germany
3. Division of Pulmonary, Department of Internal Medicine, Critical Care and Occupational Medicine, University of Iowa Hospitals and Clinics, Iowa City, IA, USA
4. Institute of Pathology, Helios University Hospital Wuppertal, Wuppertal, Germany
5. Division of Thoracic Surgery and Lung Transplantation, Department of Cardiothoracic Surgery, University Hospital of Münster, Münster, Germany