Surprisingly, as shown in Fig. 2a, IFN-α production by pDCs was enhanced in SLE when stimulated with a TLR7 ligand, imiquimod, and there was a greater increase in the percentage of IFN-α+ pDCs in patients with SLE with active disease compared to those with inactive disease. This evidence concerns the gene TLR7 and systemic lupus erythematosus.