Previous work has indicated that virus infection induces the coordinated activation of three distinct sets of transcription factors, NF-κB, IRF3 and 7, and ATF2/cJun, which together with the architectural protein HMG I(Y) bind cooperatively to the nucleosome-free enhancer/promoter of the IFNβ gene and form a nucleoprotein structure known as the enhanceosome (24, 90–95) (Figure 1). Here, IFNB1 is linked to viral infectious disease.