Overexpression of DHX9 leads to enhanced Ifnb promoter activity in response to poly I:C. Fold activation of the Ifnb promoter in HEK293T cells transfected with IFN-β luciferase reporter (100 ng) plus MyD88, IPS-1, DHX9, or DHX9-deleted DSRM expression vectors at 20, 100, or 200 ng concentrations. The Renilla-luciferase reporter gene (2 ng) was transfected simultaneously for the internal control. At 30 h posttransfection, cells were without stimulation or stimulated for 6 h with 2.5 µg/ml poly I:C delivered by Lipofectamine 2000 and then harvested.