Under hypoxic conditions, HDAC3 has been shown to exacerbate pulmonary fibrosis by promoting epithelial–mesenchymal transition in alveolar epithelial cells [10], but whether HDAC3 inhibition can attenuate hPASMC proliferation and cytokine dysregulation in hypoxia has not been established. Here, HDAC3 is linked to pulmonary fibrosis.