KDR and central nervous system cancer: Importantly, we first discovered that HULC and ESM-1, which are up-regulated in multiple types of aggressive human cancers and create a bridge between VEGF and VEGFR to induce biological activity and contribute to cancer malignancy, including angiogenesis and invasion [29, 30], are frequently overexpressed in glioma patient tissues and positively correlated with the malignancy of patients.