Patients with AGS often carry mutations in DNA restriction factors including the 3′ exonuclease TREX1 [177, 178], dNTP restriction factor SAMHD (SAM domain and HD domain) [179, 180], RNase H2 (ribonuclease H2) [181, 182], dsRNA sensor IFIH1 (IFN-induced helicase C domain containing protein 1) [183, 184], and the dsRNA-specific adenosine deaminase ADAR1 [185]. Here, TREX1 is linked to Aicardi-Goutieres syndrome.