TGFB1 and glioblastoma: Astrocytes maintain the homeostasis of neuron metabolism and mediate neuronal communication with microglia, monocytes, and T cells.28,29 While the pathophysiology of astrocytes within GBM is not well-defined, recent work shows that reactive astrocytes secrete the anti-inflammatory cytokines TGF-β, IL-10 and granulocyte colony-stimulating factor (G-CSF) that also have immune suppressive properties.30–32