CXCR4 and diabetes mellitus: Our results are supported by the observations by Dai et al.30 demonstrating that the percentage of EPCs expressing CXCR7 but not CXCR4 was reduced in a diabetes mouse and in vitro model, but not Vigorelli et al.57 who showed reduced CXCR4 protein expression when exposing CD34+ cells to a high glucose environment in vitro.