The contribution of DN T cells to the pathogenesis of autoimmune diseases depended upon a proinflammatory phenotype, and the secretion of proinflammatory lymphokines, like IL‐1 β, IL‐17, and IFNγ, and possibly autoreactive TcRs that strongly bind amino acid residues on HLA molecules. The gene discussed is IL17A; the disease is autoimmune disease.