Type 1 diabetes is an autoimmune disease in which the immune system mistakenly attacks insulin-producing beta cells in the pancreas. Without these cells, the body cannot maintain proper blood glucose levels in response to daily activities, such as eating or exercise. Generally, at the time of type 1 diabetes diagnosis, 60% to 85% of the diabetic person's beta cells have already been destroyed. However, between 15% and 40% of these cells remain and are able to produce insulin. Treatment that slows the destruction of additional beta cells may be able to decrease a patient's reliance on insulin and improve their quality of life.