The number of alveolar in hyperoxia + Hdac3−/−-treated mice was notably higher than that in the BPD mice, while the number in hyperoxia + Hdac3−/− + miR-17-antagomir-treated mice was similar to that in the hyperoxia-induced BPD mice (Fig. 6d). The gene discussed is HDAC3; the disease is bronchopulmonary dysplasia.