Significant positive correlations have also been recorded between CCN3 levels and titers of RA-specific anti-cyclic citrullinated peptide antibody (anti-CCP Ab), and between CCN3 and IL-6 expression; no such associations have been observed between CCN3 and RF, or CCN3 and TNF-α [13]. This evidence concerns the gene CCN3 and rheumatoid arthritis.