According to an article by Derek Whitney, “As early as 1990, patients with immune disorders have been successfully treated by introducing genetic material into the patient's white blood cells. While the material must be constantly introduced to the patient and is not a permanent cure, GT has been shown to dramatically improve the quality of life of patients suffering from this type of disease." On September 4, 1990, a four-year-old girl became the first GT patient. She had adenosine deaminase deficiency (an immune disorder) which left her defenseless against infections. They took white blood cells and replaced them with normal genes to produce adenosine deaminase. Ten years later she was still healthy and benefiting from the treatment. He had developed a stronger immune system and maintained a normal white blood cell count. GT has also had a huge impact on leukemia patients. At a cancer center in Pennsylvania, lymphocytic leukemia patients had their T cells removed and genetically rebuilt to become weapons against cancer cells. 26 of the 59 patients are now cancer-free. Many people may believe that the downsides of GT are too risky to attempt, but with the success it has had with such serious illnesses, it may be worth the risk and time.