A significant positive correlation was seen between serum FSTL1 levels and serologic parameters of disease activity, including ESR, CRP, RF and ACPA, with levels of clinical parameters including swollen joint count and patient global VAS and, importantly, with disease activity, as indicated by the DAS28 score in the adult RA population (Figure 6). This evidence concerns the gene FSTL1 and rheumatoid arthritis.