In accordance to our studies, a recent report confirmed that in the MRL/lpr lupus-prone mice, TLR9 deficiency in B cells is sufficient to exacerbate lupus nephritis, whereas TLR9 deficiency in pDCs, cDCs, macrophages, monocytes and/or neutrophils has no effect in disease development (58). Here, TLR9 is linked to systemic lupus erythematosus.