Additionally, 25–100 μM curcumin was shown to induce apoptosis and inhibit PGE2, by down-regulating anti-apoptotic Bcl-2 and the X-linked inhibitor of the apoptosis protein and upregulating pro-apoptotic Bax expression, in a concentration-dependent manner, on synovial fibroblasts obtained from patients with RA [285]. Here, BCL2 is linked to rheumatoid arthritis.