TLR3 and Autoimmunity: TLR3 appears to exist as a functional receptor on the cell membrane more frequently than other endosomal TLRs, probably because endogenous agonists of TLR7, TLR8, and TLR9 are more abundant than dsRNA in uninfected cells, and therefore surface localization of TLR3 poses a lower risk of autoimmunity (49).