In summary, our findings implicate the cGAS‐STING pathway in RNase H2 AGS and, together with the previously attributed role in Trex1 deficiency, suggest it is the most common signalling pathway driving inflammation in AGS, relevant also to the pathogenesis of SLE (Lee‐Kirsch et al, 2007; Günther et al, 2015). The gene discussed is JAG1; the disease is systemic lupus erythematosus.