PECAM1 (CD31) and CDH5 (VE-cadherin) are pan-endothelial markers confirming endothelial identity, while MECOM and ENPEP further support this. ACKR1 (atypical chemokine receptor 1, also known as DARC) shows enriched expression in venous endothelial cells and is involved in chemokine scavenging. Together these markers identify venous ECs and distinguish them from capillary, arterial, and lymphatic endothelial subtypes.