Therapeutic induction of vascular growth may provide a treatment option for those patients with myocardial or peripheral ischemia who are not suited to conventional revascularization therapies. Some lymphatic vascular disorders may also be amenable to this therapy. However, clear evidence of efficacy must be obtained from phase 2 and 3 clinical trials before these new treatments can be entered into clinical practice. Apart from the clinical applications, gene transfer aimed at stimulating or blocking vascular growth with various growth factors, cytokines, transcription factors and receptors or their antagonists is useful for analyzing the effects of those molecules on the vasculature, especially when gene targeting results in lethality or when large animal models are required.