CXCL8 and idiopathic pulmonary fibrosis: Among the cytokines/chemokines, chemokine CC motif ligand 18 (CCL18) [10] and interleukin-8 (IL-8) [3] have been reported to be associated with IPF prognosis, but comprehensive evaluation of cytokines/chemokines as biomarkers of IPF has not been performed.