HGF and glioblastoma: The downstream signal transduction mediators of HGF/MET signaling in gliomas include Ras/MAPK, PI3K/Akt, and STAT pathways, which mediate a variety of cellular behaviors including proliferation, survival, cell cycle progression, angiogenesis, invasion, migration, stemness, and therapeutic resistance and recurrence in glioblastomas [15–20].