IFIH1 and Aicardi-Goutieres syndrome: Gain-of-function MDA5 mutations or ADAR1 deficiency can cause PKR-mediated translational shutdown and severe autoimmune disorders, including Aicardi-Goutières syndrome (AGS), Singleton-Merten syndrome (SMS), and other interferonopathies (Ahmad et al., 2018, Chung et al., 2018, Rice et al., 2014, Rutsch et al., 2015).