It has been reported that mice with targeted deletion of T-bet have decreased production of IFN-γ and increased production of TH2 cytokines, such as IL-4 and IL-13, leading to the spontaneous development of allergic airway remodeling (eosinophilic infiltration, airway mucous cell metaplasia, and subepithelial fibrosis) similar to pathological changes observed in the lungs of asthma patients [86]. The gene discussed is IL13; the disease is asthma.