Since SLE patients are more highly susceptible to infections, and we previously showed that EE exposure of autoimmune-prone NZB/WF1 mice reduced IFNα following in vitro TLR9 stimulation, here, we investigated the effects of chronic low-dose oral EE exposure on autoimmune disease and used TLR7 (Imiquimod) and TLR9 (ODN 2395) agonists as surrogates to mimic viral and bacterial infections in vivo. This evidence concerns the gene TLR9 and autoimmune disease.