Although Gal-9 was correlated with ACPA titers (r = 0.508, p = 0.002), there was no correlation between Gal-9 levels and erythrocyte sedimentation rate (ESR), matrix metalloproteinase-3 (MMP-3), or DAS28-ESR in RA patients with high titers of ACPA (> 200 U/ml). Here, PRTN3 is linked to rheumatoid arthritis.