Loss-of-function mutations in Trex1 are present in patients with Aicardi–Goutières syndrome as well as other autoimmune diseases such as familial chilblain lupus (Lee-Kirsch et al., 2007a; Gunther et al., 2009) and SLE (Lee-Kirsch et al., 2007b; Hur et al., 2008). The gene discussed is TREX1; the disease is Aicardi-Goutieres syndrome.