Despite some deaths the amazing potential of gene therapy is illustrated by the fact that some patients have been rescued from severe genetic disease, to live normal lives. The most spectacular effect are with diseases causing a high mortality rate at a young age. However, more minor genetic diseases will become amenable to gene therapy, especially where the target organ is accessible. An example is cystic fibrosis where treatment of the lung could be carried out by inhaling gene therapy vectors in lipid particles which carry the DNA into the cells.