Additionally, VECs were strongly connected through adherent junctions, where VE-cadherin was of vital importance for the maintenance and control of endothelial cell contacts 27, and the initial assessments of TJ proteins, such as ZO-1 and claudin-5 suggested a tumor-suppressive role, with loss/reduction resulting in increased metastasis 12, 16. Here, CLDN5 is linked to neoplasm.