Description: IC50 Value: <2nM( for VEGFR2) ZM323881 is a novel VEGF-R2 selective inhibitor, which has a potent and selective inhibitor of VEGF-R2 tyrosine kinase in vitro (IC(50) < 2 nM), compared with other receptor tyrosine kinases, including VEGF-R1 (IC(50) > 50 microM) [1]. M323881 inhibited activation of VEGFR-2, but not of VEGFR-1, epidermal growth factor receptor (EGFR), platelet-derived growth factor receptor (PDGFR), or hepatocyte growth factor (HGF) receptor [2]. in vitro: ZM323881 inhibits VEGF-A-induced endothelial cell proliferation (IC(50) = 8 nM) and VEGF-R2 tyrosine phosphorylation in vitro[1]. The VEGF-induced elevation of LpA/Vi was blocked by the selective VEGF-R2 inhibitor ZM323881 [3]. Stimulation of FTC133 cells with exogenous VEGF enhanced ID3 expression, which could be abrogated by the inhibitor ZM323881 [4]. in vivo: VEGF-A-mediated increases in vascular permeability in perfused mesenteric microvessels in vivo were reversibly abolished