TREX1 and Aicardi-Goutieres syndrome: Interestingly, AGS can also be triggered by mutations in single-stranded DNA (ssDNA) 3′–5′ exonuclease TREX1(DNASEIII) [61], double-stranded RNA (dsRNA)-editing enzyme ADAR1 [62], and dNTP triphosphatase SAMHD1[63].