Donald N Mitchell MD FRCPHon Consultant PhysicianRoyal Brompton and University College HospitalsLondon, UKDavid R Moller MDProfessor of Medicine and DirectorSarcoidosis Clinic and Research ProgramDepartment of MedicineThe Johns Hopkins University School of MedicineBaltimore, Maryland, USAStephen G Spiro BSc MD FRCPProfessor of Respiratory Medicine and Honorary Consultant PhysicianUniversity College London and The Royal Brompton HospitalLondon, UKAthol Wells MBChB MD FRACP FRCP FRCRProfessor of Respiratory Medicine and Head of Interstitial Lung Disease UnitThe Royal Brompton HospitalLondon, UK