If a fully activated CD4+ T cell happens to cross-react with self-peptides presented on mTECs (in complex with the MHC-II molecules), then this self-reactive CD4+ T cell will be converted into a clone of CD4+ regulatory T (TREG) cells, which will help suppress autoimmunity in the body (discussed in Section 2.6). This evidence concerns the gene CD4 and Autoimmunity.