IFNA1 and cancer: IFNα/βexpression. The novel oncolytic poxvirus JX-795 vector (B18R deletion VV mutant) with cloned IFNβ gene (TK-/B18R-/IFN-beta+) demonstrated IFN-dependent cancer selectivity and efficacy in vitro, and tumour targeting and efficacy in mouse models in vivo [37].