In pulmonary arterial hypertension, hypoxia-induced mROS inhibit HIF-1α hydroxylation via the HIF-1α/PDK1/PDK2/p-PDH-E1α axis, triggering glycolytic shift in pulmonary artery smooth muscle cells (PASMCs), leading to lactate accumulation and histone lactylation. The gene discussed is HIF1A; the disease is pulmonary arterial hypertension.