Remarkable insights into the dynamic biology behind these processes was gleaned from studies of the monogenic disease known as Aicardi-Goutières syndrome (AGS) (127–132), in which loss-of-function mutations in any one of a number of enzymes lead to constitutively high production of type I interferons (IFNs), neurological deficits due to IFN toxicity, and autoimmunity that resembles SLE very much. Here, IFNA1 is linked to systemic lupus erythematosus.