TLR9 and systemic lupus erythematosus: In systemic lupus erythematosus, autoantigens produced type I interferon (IFN) through the Toll-like receptor (TLR)-7 or TLR-9 pathway, which triggered autoimmune response.324 Hormone receptor gene expression analysis showed that the peripheral blood mononuclear cells of patients suffering from systemic lupus erythematosus exhibited an increase in the expression of ERα mRNA, while ERβ expression decreased.