Gene therapy involves the introduction of foreign DNA into somatic cells to produce a therapeutic effect. The therapeutic gene is transferred into the tumor cells using a vector. Transfer may either be in vivo in which the DNA and vector are directly introduced into the body, or ex vivo, in which cells are removed from the body, transfected with DNA and then reintroduced into the patients. The mode of gene transfer can be classified into chemical, physical and viral (1). Viruses are the most popular vectors in clinical trials because they invade cells and manipulate the cell's machinery to make viral protein; but the immune response they provoke can rapidly destroy the viral vector or the infected cells, blocking production of the useful protein. Most nonviral vector fly under the radar of immune system, but most of them have not been as efficient as viruses in shuttling genes into cells and the genes that were delivered didn't remain active for long. Intra-arterial administration can have advantages over intravenous, and intralesion routes.