ACKR3 and diabetes mellitus: Saline-treated EPCs (control group), normal EPCs (normal group), diabetic EPCs (diabetic group), and CXCR7-primed EPCs (CXCR7 group) were transplanted into rats with diabetes after induction of vascular injury to determine whether the elevated CXCR7 level accelerated EPC-mediated endothelial repair.