VEGFA and neoplasm: Serum exosomes containing miR-25-3p and miR-425-5p promote epithelial-mesenchymal transition (EMT) and secrete vascular endothelial growth factor (VEGF), thereby facilitating tumor metastasis through activation of the PI3K/Akt signaling pathway that regulates PTEN-induced macrophage M2-type polarization.