According to a glioblastoma multiforme (GBM) model in a previous study, exosomes derived from hypoxic GBM cells can program endothelial cells to secrete potent cytokines, stimulate PI3K/AKT signaling in pericytes, and, thus, facilitate tumor vascularization and pericyte vessel coverage (47). This evidence concerns the gene AKT1 and glioblastoma.