IRF3 is a member of the interferon regulatory transcription factor (IRF) family. IRF3 has been further characterized and shown to contain several functional domains including a nuclear export signal, a DNA-binding domain, a C-terminal IRF association domain and several regulatory phosphorylation sites. IRF3 is found in an inactive cytoplasmic form that upon serine/threonine phosphorylation forms a complex with CREBBP. IRF3 can inhibit cell growth and plays a critical role in controlling the expression of genes in the innate immune response. Aggregated MAVS have been found to activate IRF3 dimerization.