TLR9 and systemic lupus erythematosus: Despite the accumulating evidence that dysregulated TLR signaling contributes to the pathogenesis of lupus in animal models, limited information is currently available concerning its role in human diseases except for several recent reports on the upregulated expression of TLR7 and TLR9 in B cells from lupus patients [22], [30], [31], [32], [33].