Again, the MAVS complexes assemble through CARD–CARD interactions, and while no auto-activating mutations are known in humans for MAVS itself, gain of function mutations are found in both mda5 and RIG-I and are associated with type I interferonopathies such as Aicardi-Goutières syndrome (AGS) and Atypical Singleton-Merten syndrome (SMS) (Rice et al., 2014; Jang et al., 2015; Rutsch et al., 2015). The gene discussed is IFIH1; the disease is Aicardi-Goutieres syndrome.