In the 1930's, Wendell Stanley first showed the virus as a crystal . Up until then it was thought that living things and material things, such as crystals, were completely different. What Stanley showed is that living things, the people, plants and animals around us, were made up of chemicals. This illustrated the similarities between the living and physical worlds. What we showed is that we could redesign the instructions of the virus so that it would go to other parts of the body and reproduce itself there.
Gene therapy is one use.
Gene therapy is the use of genetic information that can be used in medicine to cure people. Many of the most widespread diseases are caused by damaged genes. For example if you are a hemophiliac and your blood does not clot if you get a cut, the doctor may be able to cure that disease by reprogramming the genes. Most diseases can be greatly affected by changing the pattern of gene expression. Heart disease, brain tumors, cancer and HIV all could potentially be cured using gene therapy strategies.