This cancer tropism, often referred to as oncotropism, in OVs has been accomplished through various approaches: (i) engineering OVs to specifically target cancer cells, either in the entry stage or during post-entry replication steps; (ii) utilizing IFN-sensitive viruses that cannot replicate in normal cells but thrive in cancer cells with defective IFN pathways; (iii) crafting OVs devoid of one or more immune-evasion genes; and (iv) harnessing the unique metabolic pathways of cancer cells. The gene discussed is IFNA1; the disease is cancer.