Furthermore, XAF1 has been identified as an interferon-stimulated gene (ISG), which's expression is up-regulated by the exposure to IFN-α and IFN-β, resulting in a sensitization of various tumour cell lines to tumour necrosis factor-related apoptosis inducing ligand (TRAIL)-induced apoptosis [19,36]. This evidence concerns the gene IFNA1 and neoplasm.