FN1 and endothelial dysfunction: Endothelial‐to‐mesenchymal transition (EndMT) in endothelial dysfunction is another source of MFBs (13); in this process, endothelial cells downregulate vascular endothelial (VE)-cadherin, CD31 and CD34 and express mesenchymal cell markers including α-smooth muscle actin (α-SMA), collagen I and III, and fibronectin (FN).