Table 2. Therapeutic gene transfer by viruses for metastatic cancer treatment.

Gene	Function	References
Granulocyte macrophage colony-stimulating factor (GM-CSF)	Stimulate adaptive immunity against tumor associated antigen	[56, 57]
Interleukin – 12 (IL-12)	Stimulate the IFN-γ secretion and recruitment of tumor specific T-cell	[58, 59]
KAI1	Inhibit the EGFR signaling, which associated with cell motility	[61]
NM23	Reduce the cell flexibility necessary for cytoskeleton plasticity and cell motility	[62–65]
TGF-β receptor II (TGF-βRII)	Bind with TGF-β and inhibit the TGF-β signaling pathway, which associated with cancer metastasis	[69]
Osteoprotegerin linked Immunoglobulin G (OPG linked IgG)	Bind with nuclear factor kappa-B ligand (RANKL), which associated with microenvironmental conditions to influence cancer cell metastasis	[70 - 72]