Gene therapy consists of modifying the DNA sequence to replace the gene coding for the disease with a healthy gene. Germ line gene therapy does this by targeting the germ cells; this means that once the egg is fertilised, every cell which descends from the egg contains the modified gene, and therefore the person will always be free of the disease. Somatic cell gene therapy consists of altering the defective DNA of targeted body cells. This means that the effects will be short lived as the cells are destroyed and news ones with the 'defective' DNA are reproduced which causes the disease. With this approach, repeated treatments will be needed, and so is inefficient in comparison with germ line gene therapy. As germ line gene therapy is associated with much controversy, where do people stand with it ethically? What kind of regulations are set in place to control the use of it?