As shown in Fig. 1, serum Gal-9 concentrations in patients with RA were significantly higher compared to those in healthy subjects (median 7577 pg/ml [interquartile range (IQR) 5570–10,201] versus 4738 pg/ml [IQR 4267–5630], p = 0.001). This evidence concerns the gene LGALS9 and rheumatoid arthritis.