TLR9 and systemic lupus erythematosus: Consistent with results seen by Tao et al. investigating TLR9, the exonic region rs352139A/G SNP has been mildly associated with SLE (P = 0.040), with genetic analysis in a Japanese population indicating that carrying the G allele of this polymorphism predisposes individuals to an increased risk of SLE through the downregulation of TLR9 expression levels in reporter gene assays [28].