FAT1 and glioblastoma: And since hypoxia and TNFα are known activators of NFкB pathways in GBM [30, 33], on exposure of pGL3F1-FAT1-promoter transfected GBM cells to severe hypoxia (0.2% O2), TNFα and NFкB (RelA) (RelA+IKBK overexpressing vectors) increased the pGL3F1-promoter activity.