Mutations in human ADAR1 and IFIH1 cause Aicardi-Goutières syndrome (AGS), a genetically determined inflammatory disorder particularly affecting the brain and skin (Rice and al, 2012; Rice et al, 2014), belonging to a broader disease grouping referred to as the type I interferonopathies (Stetson and Crow, 2022). The gene discussed is ADAR; the disease is Aicardi-Goutières syndrome.