CXCL16 and rheumatoid arthritis: It was also determined that CXCL16/CXCR6 contributed to pulmonary fibrosis in RA-ILD patients by up-regulating proliferation and collagen accumulation of human pulmonary fibroblasts (MRC-5 cells) mediated by the PI3K/AKT/FOXO3a pathway [159].