Elizabeth M Kluka1, Philippe R Bauer1, Marie Christine Aubry2, Jay H Ryu3. 1. Division of Pulmonary and Critical Care Medicine, Mayo Clinic, Rochester, MN. 2. Department of Anatomic Pathology, Mayo Clinic, Rochester, MN. 3. Division of Pulmonary and Critical Care Medicine, Mayo Clinic, Rochester, MN. Electronic address: ryu.jay@mayo.edu.