CCL17 and idiopathic pulmonary fibrosis: In the discovery cohort, C-C motif chemokine ligand (CCL)17 could reliably predict ILD progression, particularly in patients with ILD other than IPF, and showed significant associations with mortality (hazard ratio [HR] 3.70; 95% confidence interval [CI] 1.19–11.49; P = 0.015; cut-off value = 418 pg/mL).