EDN1 and meningioma: First, due to the lack of tumoral blood supply, meningiomas secrete angiogenic factors (such as VEGF-A, endothelin-1, and caveolin-1), which can lead to increased permeability of tumoral vessels and development of the peritumoral pial vascular network, ultimately leading to alterations in the extracellular matrix and plasma protein leakage [34–38].