The second mechanism through which TCDD may suppress Th17 cells may result from its ability to increase the expression of FoxP3 and to induce more Tregs, as seen in the current study using PTX and as seen in other autoimmune disease models (Kerkvliet et al., 2009; Benson and Shepherd, 2011). The gene discussed is FOXP3; the disease is autoimmune disease.