Interestingly, like mPGES-1, HMGB1 levels in the RA synovium are reduced by intra-articular treatment with glucocorticoids, but remain unaltered in patients on anti-TNF therapy 25, 26, suggesting that HMGB1 might be a potential inducer of mPGES-1 in inflamed tissue. Here, TNF is linked to rheumatoid arthritis.