With respect to the TLR4-mediated pathogenesis of RA, TLR4 inhibition reduces the severity of CIA and joint IL-1 expression [10], while IL-1-induced joint inflammation depends on TLR4 activation [11], suggesting that IL-1 signaling is associated with TLR4-mediated immune regulation in the joints. Here, TLR4 is linked to rheumatoid arthritis.