Type 1 diabetes, also known as juvenile diabetes, is an autoimmune disease that usually presents in children and young adults. In patients with Type 1 diabetes, the body attacks itself, thus destroying insulin-producing cells in the pancreas that regulate blood sugar (glucose). A diagnosis of Type 1 diabetes currently translates to a lifetime burden of insulin injections and a risk of multiple complications for children in Canada. T-cells are white blood cells and play a key role in the immune system to control infection. In healthy individuals, a type of T-cell, called Th17, provides a strong defense by guiding the immune system to attack bacteria and virus-infected targets within our bodies. A recent discovery of elevated numbers of Th17 cells in children newly diagnosed with Type 1 diabetes suggests that these cells may play a key role in the early development of this disease in young patients. Interestingly, Th17 cells have been associated with other autoimmune diseases, such as Crohn's disease and multiple sclerosis. Dr. Ashish Marwaha is working to identify novel treatments for Type 1 diabetes by understanding the function of Th17 cells in the course of a child developing Type 1 diabetes. To understand if there is a specific genetic mutation that can predict which children will have high levels of Th17 cells and therefore at risk of developing Type 1 diabetes, he will be analyzing stored blood samples from British Columbian children with this disease. The findings from this study will determine the extent to which Th17 cells are harmful in Type 1 diabetes and may open the door to new treatments for childhood diabetes that target Th17 cells.