IFNL1 and rheumatoid arthritis: Because IL-29 and TLR2, TLR3 and TLR4 have all been reported to be highly expressed in RA synovium and to induce IL-6 and IL-8 expression in RA-FLSs, we further investigated the potential regulatory relationship between cytokines IL-29, IL-6 and IL-8 and TLR2, TLR3 and TLR4 in RA-FLSs.