NOTCH1 and glioma: ELTD1 has emerged as an angiogenic biomarker, co-regulated with other angiogenic factors, such as VEGF, NOTCH1, and DLL4.113,114ELTD1 is transcriptionally upregulated in blood vessels of high-grade glioma tumors compared to vessels from low-grade gliomas and from nonmalignant control tissue.