Gene therapy for cardiovascular diseases
Several cardiovascular diseases are due to abnormalities in muscles of the hearts or blood vessels. In cases of arteries blockage, when arteries are openeo using baloon angioplasty, reblockage (also called restenosis) occurs in 50% cases and can be treated by gene therapy. Gene therapy has been attempted for several of these diseases.

For instance, blockage of arteries caused by proliferation of smooth muscles lining the artery walls, can be treated by gene encoding thymidine kinase (tk) carried by adenovirus. Thymidine kinase makes the proliferating cells susceptible to a drug called ganciclovir. Similarly, the gene for vegf (vascular endothelial growth factor) has been used for growth of new blood vessels for the heart. The vegf gene may be transferred through a virus or via liposomes.