Ishimaru et al. (104) demonstrated that three low dose TCDD exposures in neonatal mice disrupted thymic selection, enhanced production of Th1 cytokines from splenic CD4+ T cells, and increased autoantibodies in the sera of TCDD-exposed mice compared with those in control mice indicating that early exposure to environmental contaminants and consequent AHR signaling in the neonatal thymus alters differentiation and/or development of T cells associated with autoimmunity (104). The gene discussed is AHR; the disease is Autoimmunity.