TLR3 and rheumatoid arthritis: Interestingly, cells from RA patients (n = 20) secreted significantly larger amounts of IL-1β compared to controls (n = 18) upon cell priming with TLR3 or TLR4 ligands (Fig. 4a, b), while IL1-β secretion was comparable when TLR2 ligand was applied (Fig. 4c).