Type 1 IFN produced by pDCs has beneficial roles in host immunity to viral infections (9, 10), but it is also implicated in the pathogenesis of certain types of autoimmune diseases, including systemic lupus erythematosus (SLE) (11, 12), especially through an aberrant TLR7 activation (13, 14). Here, TLR7 is linked to systemic lupus erythematosus.