VCAM1 and neoplasm: In addition to the abnormalities of tumour blood vessels and interstitial pressure towards the vessel lumen, reduced expression of adhesion molecules for rolling and firm adhesion of lymphocytes on tumoural endothelial cells (e.g., intercellular adhesion molecule-1 and -2 for lymphocyte function-associated antigen-1, and vascular adhesion molecules [VCAM]-1 for very late antigen [VLA]-4) is the cause of impaired extravasation of lymphocytes into tumour lesions39–42.