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). Here, TREX1 is linked to Aicardi-Goutieres syndrome.