ITGA9 and pulmonary emphysema: For example, multiple genes in the AT1 cell program were closely related to pulmonary veno-occlusive disease (PVOD) (Bmpr2 and Eif2ak4), lung cancer (Itga9 and Braf), pulmonary fibrosis (Cadm1 and Itgb6), pulmonary hypertension (Bmpr2 and Cav1), and pulmonary emphysema (Itgb6).