Activation of IRF3 and induction of type I IFNs protect the host against infection and cancer, but excessive IFN responses triggered by self-DNA (including mtDNA) under sterile conditions cause autoinflammatory conditions such as Aicardi–Goutières syndrome (AGS), STING-associated vasculopathy of infancy (SAVI) and systemic lupus erythematosus (SLE) [158, 159]. Here, STING1 is linked to infection.