TGFB1 and glioblastoma: Some signaling pathways that activate the EMT-TFs in GBM include those mediated by transforming growth factor β (TGF-β) [22], receptor tyrosine-kinases (RTKs) [23,24,25], wingless-integration (Wnt)/beta-catenin [26,27], hypoxia [28,29], inflammatory cytokines such as interleukin 6 (IL-6) [30], and steroid hormones such as 17β-estradiol (E2) [31].