PECAM1 and diabetes mellitus: Diabetes reduced the formation of arterioles (vessels <30 μm) and capillaries (CD31-positive vessels <10 μm) in response to tissue ischemia by 36% (P = 0.0007; Figures 3A,C) and 38% (P = 0.0021; Figures 3A,D), respectively, compared to normoglycemic littermate controls.