TLR4 and rheumatoid arthritis: It has been reported that type I IFN induces TLR2, TLR3 and TLR4 expression in RA-FLSs; therefore, we examined whether IL-29 enhances TLR2-, TLR3- and TLR4-mediated IL-6 and IL-8 expression in RA-FLSs through increased TLR expression.