PECAM1 and diabetes mellitus: In contrast, the percentage of CD31-positive endothelial cells in the glabrous skin of the hind paw was significantly higher 4 weeks after induction in diabetic rats than in controls (Control: 6.6 ± 0.7% vs. 4 weeks diabetes: 12.9 ± 1.9%; p < 0.05) (Fig 4a).