This study will prospectively include all patients at the two centres in Denmark where patients are treated for IPF and has thus a good opportunity to include the majority of incident cases of IPF in Denmark. The serum levels of several promising biomarkers will be measured at baseline and during one year follow-up. Patients will also be followed up through regular clinical examination and by querying national registries to determine disease progression, mortality, healthcare utilization and selected co-morbidities such as malignancy. The database will be used for determination of risk factors for the outcomes listed above. Sub-group analyses are planned in respect to sex, radiologic imaging at baseline (e.g. honeycombing), smoking status, co-morbidities (both pulmonary disease and extra-pulmonary disease), and disease severity at baseline.