TLR9 and systemic lupus erythematosus: Likewise, 13 of the 14 SLE subjects with impaired TNF-α production upon TLR-9 stimulation (HCQ vs no HCQ; P < 0.009) and 12 of the 13 subjects with impaired TNF-α production upon TLR-7 stimulation (HCQ vs no HCQ; P < 0.01) were being treated with HCQ.