Contrary to a pro-Th2 effect of c-Maf on the immune response, increased Th2 lung pathology, associated with higher numbers of eosinophils in bronchoalveolar lavage fluids, was observed in the HDM allergy model despite a decreased expression of Il4 in T-cell specific c-Maf deficient mice (67). The gene discussed is MAF; the disease is allergic disease.