TLR7 and arthritic joint disease: Toll‐like receptors (TLRs) constitute a membrane protein family and their activation is associated with the production of pro‐inflammatory cytokines and the activation of different immune cell populations.[205] The arthritis‐inducing capability of TLR ligands has been demonstrated in animal experiments,[206] and TLR‐specific antagonists successfully alleviated CIA.[207] Given the abundant expression of TLR7 in the synovial intimal and subintimal regions of RA joints,[208] Chen et al.