Gene therapy designates both the introduction of new DNA as replacement for absent or defective genes and the suppression of endogenous gene products. Introduction of new DNA by plasmid or virus vectors as well as suppression of gene expression by antisense oligonucleotides have been shown to inhibit neointima formation after arterial injury. However, present vectors and oligonucleotides have significant limitations in terms of efficiency of gene transfer and maintenance of expression of introduced DNA. Furthermore, our lack of knowledge regarding the appropriate targets for gene therapy in restenosis makes this approach speculative...