H&E staining shows, SftpcCreert2/+R26LSL-Hif3a group has much better mean liner intercept (MLI) and mean alveolar number (MAN) compared with R26LSL-Hif3a group, suggest the higher level of lung integrity, alveolar numbers and less presence of emphysema (Figure 6A-C). The gene discussed is HIF3A; the disease is pulmonary emphysema.