In these animals (as well as in appropriate controls), AHR remained low, no airway inflammation was observed and no increased levels of total serum IgE were found (Veh: 221.4 ± 66.5 ng/ml vs. TDI: 264.9 ± 105.7 ng/ml) thus confirming the importance of B-lymphocytes in our model (data not shown). This evidence concerns the gene IGHE and inflammation.