Analysis of a cohort of connective tissue disease-associated ILD, chronic hypersensitivity pneumonitis and unclassifiable ILD patients’ serum samples at diagnosis identified and validated 17 novel biomarkers associated with progressive pulmonary fibrosis, including CXCL17 (C-X-C motif chemokine ligand 17) and TGFA (transforming growth factor alpha) (60). This evidence concerns the gene CXCL17 and connective tissue disorder.