KDR and neoplasm: The major target of Apatinib is the VEGFR-2/kinase insert domain receptor (KDR), selectively inhibiting the activities of VEGFR-2, as well as blocking the signal transduction of the binding of VEGF to receptors, effectively inhibiting the cellular processes (proliferation and migration of endothelial and tumor epithelial cells), thereby inhibiting tumor angiogenesis and exerting anti-tumor effects [16, 17].