THBS1 and glioblastoma: Glioblastoma cells secrete, in vitro and under hypoxic conditions, exosomes that contain protein-lysine 6-oxidase (LOX), thrombospondin-1 (TSP1), vascular endothelial growth factor (VEGF) and metalloproteinase with thrombospondin motifs 1 (ADAMTS1).