KDR and neoplasm: However, this assumption needs to be thoroughly re-evaluated, in light of recent VEGFR2-immunostaining that localized VEGFR2 equally on luminal and abluminal surfaces of tumor- and adenoVEGF-induced microvascular endothelium, as well as significantly on transendothelial vesiculovaculolar organelles (VVOs) and luminally-attached caveolae [162].