Microglia in the brain tumor microenvironment also secrete multiple growth factors and cytokines, such as transforming growth factor beta (TGFβ), TNFα, IL1, IL6, VEGF, epidermal growth factor (EGF), as well as metalloproteinases, which further promote tumor proliferation and invasion in addition to supporting angiogenesis [44,45,56]. This evidence concerns the gene EGF and neoplasm.