High endothelial venules (HEVs) are specialized postcapillary venules
found in lymphoid tissues that support high levels of lymphocyte extra
-vasation from the blood. Here, Jean-Philippe Girard and Timothy Sprin
ger highlight the unique properties of HEV endothelium, discuss the mo
lecular mechanisms controlling HEV specialization and review evidence
suggesting that HEVs could play an important role in the pathogenesis
of chronic inflammatory diseases.