We next investigated whether the interaction between IRF5 and TRIM21 could be affected by TLR stimulation, previously shown to enhance TRIM21 affinity for its substrates, focusing in particular on the TLR7 pathway known to activate IRF5 and of primary importance in SLE [5], [16], [21], [31], [32]. This evidence concerns the gene TLR7 and systemic lupus erythematosus.