Classes of trans genes that can be inserted into OV vectors include: (1) genes whose products can induce cancer cells to undergo apoptosis/necrosis, such as TRAIL [13,14]; (2) gene products that inhibit tumor-associated angiogenesis [15], such as IL-12 [16]; (3) Th1-stimulatory cytokines such as IL-2, IL-15 [17,18,19]; and (4) genes that encode antibodies that recognize one or more accessible tumor-associated and/or immune cell-associated antigens. The gene discussed is IL2; the disease is neoplasm.