The effect of G knockdown on type I Interferon induction. A549 cells were transfected with siMM, siG2 or were not transfected prior to infection with hMPV at a MOI of 2, or mock infection with media. UV-inactivated hMPV was used as a control for interferon induction. Transcription of mRNA encoding human IFN-α (a) and IFN-β (b) was measured by RT-qPCR 24 h post-infection. There was a moderately significant increase in IFN-β mRNA in siG2 transfected cells compared to untransfected cells (*P = 0.03; t-test) and cells transfected with siMM (**P = 0.02; t-test) prior to hMPV infection. Data was normalised to β-actin and expressed relative to uninfected cells. (c) A reduction in G did not affect IFN-β secretion from cells transfected with either siMM or siG2 prior to hMPV infection, compared to untransfected and infected cells. Supernatants were collects on days 1, 2 and 3 post-infection for ELISA analysis.