As mutations in the genes encoding both TREX1 and the trimeric RNase H2 complex cause autoinflammation in AGS (Crow et al, 2006a,b2006b), it has been proposed that RNase H2-AGS results from the failure to degrade the RNA:DNA intermediates of endogenous retroviruses (Stetson, 2009). The gene discussed is TREX1; the disease is Aicardi-Goutieres syndrome.