Dysfunction of TREX1 leads to accumulation of cytosolic nucleic acids and a range of autoimmune diseases, such as Aicardi–Goutières syndrome (AGS), systemic lupus erythematosus (SLE), retinal vasculopathy, cerebral leukodystrophy and familial chilblain lupus (FCL) (4–6). This evidence concerns the gene TREX1 and systemic lupus erythematosus.