CCL15 and idiopathic pulmonary fibrosis: The Myeloid-enriched IPF subset (Subset 1) had increased expression of XCL1, CCL17, CCL5, CXCL9, CXCL10 and CXCL11, whereas the Ciliated epithelium-enriched IPF subset (Subset 2) had increased expression of CCL15, CXCL1, CXCL6, CCL7, CXCL17, CXCL13, CCL14 and CXCL14.