Although relatively small, initial phase II studies and recent retrospective meta‐analyses have suggested that interferon‐α (IFN)/zidovudine (AZT) therapy may be promising for cancer types with leukemic manifestation, however, the therapeutic effects of IFN/AZT are not considered to be attributable to direct cytotoxic effects on leukemia cells 43, 44. This evidence concerns the gene IFNA1 and cancer.