The main research interest of our laboratory group is to examine the genetic control of autoimmune diseases to gain a better understanding of the mechanisms by which immune tolerance is broken. A major focus of our lab group is a human autoimmune syndrome called Autoimmune Polyglandular Syndrome Type 1 (APS1 or APECED), which is classically manifested by an autoimmune attack directed at multiple endocrine organs. This disease is inherited in a monogenic autosomal recessive fashion and the defective gene has been identified and is called Aire (for autoimmune regulator). Aire knockout mice, like their human counterparts, develop an autoimmune disease that is targeted to multiple organs. Through the use of the mouse model we, along with others, have determined that Aire plays an important role in immune tolerance by promoting the expression of many self proteins in specialized antigen presenting cells in the thymus called medullary epithelial cells (mTEC’s).