EIF4EBP1 and glioblastoma: Hypoxia, a common microenvironmental stress in fast‐growing tumours, previously shown to alter sEV cargos in glioblastoma cells (Kurcharzewska et al., 2013), also inhibited mTORC1, as determined by reduced phospho‐S6 and phosphorylated forms of 4E‐BP1 in western blots of cell lysates (Figure S2c).