ADAR and Autoimmunity: Clinical and genetic studies have helped to define a cell-intrinsic mechanism for the initiation of autoinflammation/autoimmunity upon human ADAR1 or mouse Adar1 deficiency: without appropriate RNA editing by ADAR1, endogenous dsRNA aberrantly activates the antiviral cytosolic dsRNA-sensing receptor MDA5, leading to the recruitment of mitochondrial antiviral-signaling (MAVS) adapter protein and to the inappropriate activation of type 1 interferon (IFN) expression, the upregulation of IFN-stimulated genes (ISGs), and cell death [1,2,4,11].