Abstract: Exosomes are microvesicles ranging from approximately 40-150 nm in size, which mediate the exchange of information between cells by releasing proteins, nucleic acids, etc. Tumor-derived exosomes (TEXs) may facilitate tumor metastasis through various mechanisms such as forming the premetastatic niche in the terminal organs, they can regulate immune cells and immune-related molecules in the tumor microenvironment to promote tumor immune escape, they can also induce tumor angiogenesis and increase vascular permeability, promoting the epithelial-mesenchymal transformation of tumor cells, etc. Understanding the mechanism of TEXs in tumor metastasis can provide new ideas for effective prevention and treatment of tumor metastasis.

Key words: Neoplasm metastasis, Neovascularization, pathologic, Tumor-derived exosomes, Epithe-lial mesenchymal transition