PECAM1 and myocardial infarction: We first described protein expression in the myocardium tissue at different time points post-MI in mice and found that KMT2D expression was also upregulated in the first 7 days after MI and gradually decreased thereafter (Figs. 1D and E), which is consistent with the content of VEGF-A in myocardium, the abundance of CD31-positive endothelial capillaries, and α-SMA-positive arterioles.