NTAN1 and neoplasm: High endothelial venules (HEVs), expressing a specific type of peripheral nodal addressin (PNAd)+ (also called MECA-79) vessel surrounding TLSs, allow immune cells, including DCs and T, B, and Treg cells, to extravasate from the circulation to the periphery for entry into the tumor and are involved in lymphocyte recruitment via the secretion of chemokines (20, 44).