RIGI and infection: Expression of C6 inhibited the activation of the IFN-β promoter by transfected poly(dA-dT) (which acts via intracellular DNA sensors) or poly(I∶C) (which acts via RLRs) in HEK293 cells (Figure 1A, B), and by infection of cells with Sendai virus which activates RIG-I signalling [4] (Figure 1C).