TLR9 and systemic lupus erythematosus: Increases in TLR9 expression have been shown in PBMCs from SLE patients and levels usually correlate with IFNα expression and anti-dsDNA antibodies (Komatsuda et al., 2008; Mu et al., 2012; Chauhan et al., 2013; Lyn-Cook et al., 2014).