HGF and astrocytoma (excluding glioblastoma): However, in normal developing brain and therefore, also in the brain tumor (microenvironment) several growth factors including VEGF, EGF, HGF, FGF and PDGF, are commonly expressed.[31–38] Interestingly, the growth factor receptors are found often to be present on low grade astrocytoma and ependymoma cells.