Previous cross-sectional studies have shown, for example, that a number of serum protein biomarkers are associated with the presence of both mild and advanced forms of RA-ILD—including MMP-7 and IP-10/CXCL1011,12,14,18,19—suggesting that these mediators contribute to the pathophysiology of RA-ILD. This evidence concerns the gene CXCL10 and rheumatoid arthritis.