To address the hypothesis that functional impairment of Treg and Teff cells are due to molecular modifications in FOXP3 and IFNγ that are linked mechanistically to outcomes of asthma, we first determined the extent to which Treg and Teff cell function was impaired in the MZT with asthma vs. the paired MZT without asthma. This evidence concerns the gene IFNG and asthma.