PECAM1 and type 2 diabetes mellitus: To explore the relationship between senescent macrophages and vascular aging in T2DM, IF staining was performed for α-SMA (vascular smooth muscle cell marker), CD31 (endothelial cell marker), F4/80 (macrophage marker), and p16 (senescence marker) in aortic samples from diabetic and healthy mice (Figure 2A).