The pro-angiogenic factor HIF-1α is targeted for destruction in normoxic environments by the hydroxylation of a specific proline residue, P564, by the oxygen-sensing enzyme HIF-1α prolyl hydroxylase (HIF-PH). DMOG is a cell permeable, competitive inhibitor of HIF-PH. It acts to stabilize HIF-1α expression at normal oxygen tensions in cultured cells, at concentrations between 0.1 and 1 mM. DMOG is therefore expected to act as a pro-angiogenic compound, acting via the HIF-1α system.