VEGFA and leukemia: Finally, EVs play an important role in leukaemia cell survival by promoting angiogenesis, either directly, by delivering IL-8 and vascular endothelial growth factor (VEGF) changing the proliferative capacity of endothelial cells [66] and delivering miR-17-192, which stimulates angiogenesis [16], or indirectly by inducing hypoxia, through delivery of hypoxia-inducible factor 1-a (HIF-1a) to endothelial cells, which respond by activation of their angiogenic properties [67].