Exosomes from glioblastoma multiforme (GBM) patients and hypoxic GBM cells accumulate high concentrations of pro-angiogenic mediators like MMP9, pentraxin 3, IL8, PDGF-AB/AA, CD26 (aka dipeptidyl-peptidase-4), and plasminogen activator inhibitor 1 (PAI-1), stimulating proliferation, migration, and angiogenesis in ECs, mouse aorta rings and human GBM xenografts [114]. Here, DPP4 is linked to glioblastoma.