KDR and neoplasm: Considering our previous study [12] along with the research mentioned above [48], we speculated that tanshinone IIA might act as a competitive inhibitor of VEGFR2, forming complexes with VEGFR2 to interdict the binding of VEGF to VEGFR2 and the phosphorylation of VEGFR2, sequentially inhibited tumour angiogenesis, cell migration and tumorigenicity [64].