HUVECs were adenovirally transduced with VE-cadherin-GFP and plated on ibidi slides (n = 4; control vs. Sema3C (− VEGF) at 20× magnification (Supplementary Movies S1 and S2)). Representative pictures are shown at time points 0 and 1 h. Arrowheads indicate gaps between endothelial cells. Scale bar, 100 μm. 