Although others highlighted each antitumour mechanism in the basic studies of IFN-α gene therapy, in this study we demonstrated that intratumoral injection of the IFN-α adenovirus could effectively suppress xenograft tumours of pancreatic cancer due to the dual mechanisms of antitumour activities: the direct regional apoptosis induction and the systemic immunological effect at least through NK cell activation. Here, IFNA1 is linked to neoplasm.