Mutations in TREX1 (three prime repair exonuclease 1) or SAMHD1 (SAM domain and HD domain-containing protein 1) (Hu et al., 2015), for instance, lead to the same autoimmune disease, Aicardi-Goutières syndrome (AGS). The gene discussed is SAMHD1; the disease is Aicardi-Goutieres syndrome.