Gene therapy using an adenovirus vector. A new gene is put into a virus, which is then put into a human. If the treatment is successful, the new gene will make working enzyme, which will treat the disease.

Gene therapy means putting in a working gene to a person who has a damaged gene. The European Commission has approved this method for one particular treatment. The treatment by the product Glybera uses a virus to infect muscle cells with a working copy of the gene. The European Commission has given Glybera marketing authorisation, which means it can be sold throughout the EU.