Finally, we tested if ABCB5+ MSCs restore ER Ca2+ using the Sarco-/endoplasmic reticulum ATPase 2a (SERCA2a)- Phospholamban (PLN) axis in both in-vitro cell models as well as in-vivo hind limb ischemia model in Apolipoprotein E knock-out (ApoE−/−) mice, which model chronic on acute hypoxia. The gene discussed is APOE; the disease is limb ischemia.