Next, the Hdac3 gene was knocked out in BPD mice, and it was verified that the abnormal cell morphology was attenuated in BPD + Hdac3−/− mice (Fig. 1a), the degree of abnormal alveolarization was notably lower (Fig. 1b), as well as the MVD was higher when compared to untreated BPD mice (Fig. 1c). The gene discussed is HDAC3; the disease is bronchopulmonary dysplasia.