TLR2 and rheumatoid arthritis: Exogenous peptidoglycan as well as endogenous ligands such as RNA from necrotic cells, hyaluronan, heat‐shock protein and fibrinogen is present in the RA synovial joint and can potentially activate synovial fibroblasts through TLR2 and TRL4 signalling and upregulate the expression of pro‐inflammatory cytokines and chemokines [29].