In thymus, which gene is responsible for recognition of self-antigens?

Immunologic tolerance is the phenomenon of unresponsiveness to an antigen induced by exposure of lymphocytes to that antigen. A protein called AIRE (autoimmune regulator) stimulates expression of some "peripheral tissue-restricted" self-antigens in the thymus It is critical for deletion or negative selection of immature T cells specific for these antigens. Mutations in the AIRE gene are the cause of an autoimmune polyendocrinopathy. In the CD4+ T-cell lineage, some of the cells that see self-antigens in the thymus do not die but develop into regulatory T cells.