FIBRALUNG is a prospective cohort study with biobank of samples from patients with pulmonary fibrosis, aiming to explore the molecular determinants of different clinical outcomes, acute exacerbations and mortality. We expect to gain deeper insight into fibroproliferative common pathways, particularly between idiopathic pulmonary fibrosis and fibrotic hypersensitivity pneumonitis, paving the way for new biomarkers that reflect the progressive phenotype, that eventually will support new targeted therapies. Other idiopathic interstitial pneumonias, connective tissue disease-related interstitial lung diseases and sarcoidosis patients will be also recruited and their biological samples stored for further analyses.