TNF and diabetes mellitus: As shown in Figure 6, the protein expressions of both CXCR4 and TNF-α were significantly increased early at 2 weeks of diabetes as compared to the control, and the DRG TNF-α and CXCR4 protein expression maintained significantly increased by 5 weeks of diabetes (Figures 6(a) and 6(b), P < 0.05, diabetes vs. control).