VE-Cadherin expression on the surface of endothelial cells following exposure to FXIa. HUVECs were seeded onto gelatin-coated glass coverslips and grown to confluence in a 24-well plate before exposure to vehicle, FXIa (30 nM), FXI (30 nM), α-thrombin (10 nM), or FXIa or thrombin in the presence of PPACK. Cells were fixed and stained for VE-Cadherin (green), together with actin (red), nuclei (blue), and visualized by immunofluorescence microscopy. Scale bar = 50 μm