Three-prime repair exonuclease 1 (TREX1) plays a very important role in preventing the immune response by degrading cytosolic DNA fragments.TREX1 mutations have been observed in both SLE and AGS patients, and cGAS is required for triggering the autoimmune response by inducing type I IFNs in these contexts [103–105] . This evidence concerns the gene TREX1 and systemic lupus erythematosus.