A cell-permeable and reversible indolin-2-one class of receptor tyrosine kinase (RTK) inhibitor [IC50 = 70 nM for VEGF-R2 (KDR/Flk-1), 920 nM for PDGF-Rβ, 4.92 μM for p60c-src, and 13.3 μM for FGF-R1]. The inhibition is suggested to be competitive with respective to ATP. Also inhibits VEGF-induced (IC50 = 110 nM) and PDGF-induced (IC50 = 2.01 μM) cell proliferation in umbilical vein endothelial cells (HUVEC). Does not exhibit any inhibitory effect on EGF-R kinase activity (IC50 >100 μM).