1 Keck School of Medicine, University of Southern California, Los Angeles, Calif.
2 Division of Pulmonary and Critical Care Medicine, Department of Medicine, Keck School of Medicine, University of Southern California, Los Angeles, Calif.
3 Division of Thoracic Surgery, Department of Surgery, Johns Hopkins School of Medicine, Baltimore, Md.
4 Division of Thoracic Surgery, Department of Surgery, Keck School of Medicine, University of Southern California, Los Angeles, Calif.