IL4 and chronic obstructive pulmonary disease: α-GalCer-induced model: 1. Repeated intranasal challenge with α-GalCer induced COPD (characterized by emphysema, mucus production, and fibrosis) 2. COPD phenotype from α-GalCer-induced IL-4-producing iNKT cells was ameliorated by anti-IL-4 mAb treatment