TLRs (especially TLR-2, TLR-3, TLR-4, TLR-5, and TLR-7 in RA) regulate the nuclear factor kappa-B ligand (NF-κB), generation of osteoclasts, and induce increased production of TNF-α, IL-6, IL-12, IL-18, and many other proinflammatory cytokines [40,43]. Here, IL18 is linked to rheumatoid arthritis.