Unclassifiable ILD

The goal of this observational study is to identify early biomarkers that can predict the development of progressive pulmonary fibrosis (PPF) in participants with interstitial lung diseases (ILDs). The participant population includes adults diagnosed with idiopathic pulmonary fibrosis (IPF), familial pulmonary fibrosis (FPF), other fibrotic ILDs, and interstitial lung abnormalities (ILA). The main questions it aims to answer are: * What biomarkers and risk factors are linked to fibrosis progression or can predict rapid worsening and sudden flare-ups in IPF and FPF patients? * What biomarkers and risk factors can predict the development of a PPF phenotype in different types of ILD? * What biomarkers and risk factors can help identify ILA patients who may develop significant ILD? * What biomarkers and risk factors can predict how well ILD patients will respond to treatment? Researchers will compare the outcomes between participants diagnosed with IPF/FPF, other fibrotic ILDs, and ILA to see if early detection biomarkers differ among these groups. Participants will: * Undergo blood sampling. * Perform lung function tests. * Have CT scans. * Perform breath analysis * Participate in exposome and microbiome analyses. * Complete questionnaires. * A subgroup of participants will be offered bronchoscopy.