ADAR and Aicardi-Goutières syndrome: Recent data in Drosophila also show that catalytically inactive Adar (fly ortholog) causes innate immune activation in brain-like tissue (Deng et al., 2020), and mutations in human ADAR1 result in Aicardi Goutières syndrome (AGS), which is characterized by type I interferon activation in the brain (Rice et al., 2012).