CXCR4 and diabetes mellitus: Indicative of a dysfunctional signaling environment in situ, the expression of multiple growth factors and cytokines (Vegf-a, Fgf-2, Pdfg-a, and Sdf-1; P <0.02) as well their associated receptors (Cxcr-4, Fgfr-2, and Pdgfr-a; P <0.01) was significantly decreased in the setting of diabetes (Figure 1A).