Unexpectedly, in all autoimmune-prone mouse models, including MRL/lpr, B6/lpr, Balb/c-Pristane, B6.Nba2.Yaa, B6 Yaa, and Ali5 deficient in TLR9, RNA-associated antibodies are increased, suggesting a more complex role for TLR9 in SLE (8, 9, 12–17). Here, TLR9 is linked to systemic lupus erythematosus.