Associated with the improvements in contractility, the CD31‐positive (CD31+) capillary and α‐smooth muscle actin‐positive (SMA+) arteriole densities in the border and infarct zones were significantly higher in the hES‐MSC treated hearts compared with the hBM‐MSC or vehicle groups at 28 days post MI (Figure 1A,B). Here, PECAM1 is linked to myocardial infarction.