TLR4 and rheumatoid arthritis: S100s (S100A8, S100A9 and S100A12) exert pro-inflammatory properties through their effects on Toll-like receptor-4 (TLR4) and the receptor for advanced glycation end produce (RAGE) signal cascades in inflammatory and immune cells15,16, which correlate with many human inflammatory diseases such as rheumatoid arthritis, inflammatory bowel disease and several auto-inflammatory diseases17,18.