In addition to providing important data on the question of how TLR9 and TLR7 cross-regulate, by showing the B cell–intrinsic role of TLR7, the present study has practical implications for developing new SLE therapies; this is particularly important given the association between human TLR7 polymorphisms and gain-of-function variants and SLE. The gene discussed is TLR9; the disease is systemic lupus erythematosus.