Dll4 and Dll4/Ang2 are sufficient to reverse endothelial HIF-2α deletion phenotypes in a hindlimb ischemia model. Blood flow, foot movement score and necrosis were assessed for Ctrl and KO mice after femoral artery ligation and intramuscular injection of an empty viral vector, a viral vector expressing Dll4 or Dll4 vector in combination with intravenous Ang2. The gene discussed is DLL4; the disease is ischemia.