IL1RL1 and glioma: However, deletion of the ST2 receptor has also been shown to favor angiogenesis.50 Here, we observe increased numbers and density of aberrant blood vessels in gliomas implanted in ST2-deficient mice, in association with increased levels of VEGF in the serum, a crucial factor known for promoting tumor vascularization and supporting tumor growth.39 This data indicates that ST2 deficiency promotes an angiogenic microenvironment, associated with the release of MMPs and angiogenic factors, which favors vascular abnormalities in glioma.