HEK293 cells were transfected with siCTL or siDDX5 and XRN2 ChIP assays were performed. The XRN2 ChIP signal was normalized to the Pol II ChIP signal. WCE were immunoblotted with anti-DDX5 and α-tubulin antibodies, the latter was used as a loading control. The graphs show the average and S.E.M. from at least three independent experiments. Statistical significance was assessed using Student's t-test. *: p < 0.05; **: p < 0.01. 