TLR7 and systemic lupus erythematosus: As circulating nucleic acid-containing complexes can stimulate plasmacytoid dendritic cells (pDCs) in systemic lupus erythematosus, some intracellular Toll-like receptors (like TLR3, TLR7, TLR8, TLR9) and their signaling pathways could be potential therapeutic targets (37).