KDR and neoplasm: Mesylate apatinib (YN968D1) is a novel oral micromolecular tyrosine kinase inhibitor that inhibits vascular endothelial growth factor receptor-2 (VEGFR-2), mainly through competitively binding the intracellular tyrosine in the adenosine triphosphate binding site of the receptor, thus highly selectively inhibiting the activity of the VEGFR-2 tyrosine kinase and blocking signal transduction after binding of vascular endothelial growth factor (VEGF), thereby potently inhibiting tumor angiogenesis and decreasing the density of microvessels in tumors19–21.