Natural Killer T (NKT) and Mucosal Associated Invariant T (MAIT) are specialised subsets of T cells that play important roles in immunity to pathogens, cancer and regulation of autoimmunity. They are collectively referred to as “unconventional” T cells because they do not recognise protein-derived antigens, like conventional CD4+ and CD8+ T cells. Instead NKT and MAIT cells recognise lipid and metabolite antigens, respectively. Like all T cells, unconventional T cells emerge from the thymus, but their development within the thymus remains poorly understood. Coronins are actin cytoskeleton regulators that regulate cellular motility, responses to extracellular signals, proliferation and other cellular process that are important for T cell development. We have discovered that NKT cells specifically express Coro2a, while MAIT cells specifically express Coro2b. This project will investigate if these two Coronins are important for regulating the development of these cells in the thymus by analysing Coro2a and Coro2b knockout mice.