The expression of miR-31-5p was downregulated and negatively correlated with the overexpression of SLC15A4 in PBMCs of SLE patients (140), the absence of SLC15A4 results in pDCs being unable to produce IFN-I in response to the TLR7/9 ligand in vivo, to counteract the excessive production of IFN-I during the course of SLE. This evidence concerns the gene SLC15A4 and systemic lupus erythematosus.