Endothelial 2 cells are distinguished by expressing high levels of claudin-5 (CLDN5), ICAM2, and the chemokine CXCL2. Endothelial 3 expresses high levels of the platelet-recruiting Von Willebrand Factor (VWF) and caveolin-1 (CAV1), a protein known to regulate cholesterol metabolism, atherosclerosis progression, and MuSC activation [21, 22]. Here, CLDN5 is linked to atherosclerosis.