This approach involves a shared longitudinal protocol conducted across all participating centers which includes common information on all SARP participants. Additionally, the SARP-SF has identified mechanistic research questions to be included in the shared longitudinal protocol. This will be explored through additional sample collections of sputum and fluids and biopsied tissue collected by bronchoscopy. Together, these longitudinal and mechanistic approaches will enable prediction of phenotype stability/fluctuation and pharmacologic responses and identification of novel, disease-modifying targets for treatment.