This ADAR1p150 function in the regulation of the MDA5-MAVS-IFN pathway underlies the embryonic lethality of Adar1-null mice17,18 and also the pathogenesis of Aicardi-Goutières syndrome (AGS; AGS1–7 subgroups known), a severe human autoimmune disease against endogenous nucleic acids14–16. The gene discussed is ADAR; the disease is Aicardi-Goutieres syndrome.