To further investigate the link between circulatory CTHRC1 and disease status, we performed multi-analyte BioLegend immunoassays on a randomly chosen subset of twenty RA patients for levels of the inflammatory cytokines IL-1β, IL-6, IL-8, and IFNγ, which are increased in the plasma of patients with RA (6, 7) and are considered indicators of the inflammatory state. Here, CXCL8 is linked to rheumatoid arthritis.