**11. Integrative overview**

EVs play an essential role in cellular communication both in physiological and pathological conditions. In pathological conditions, EVs have been implicated in cancer, spreading of viruses or other pathogens, altered immune response, development of neurodegenerative diseases, etc. In cancer, EVs ensure the cross talk between tumoral cells or between tumoral cells and nontumoral cells, and enable the development of multiple processes, including tumorigenesis, pre-metastatic niche formation, metastasis, and drug resistance. In ovarian and breast cancers, the involvement of EVs in all these processes of tumor evolution has been described and the analysis of EVs content is particularly useful for identifying biomarkers of the disease per se and, moreover, for the stage of the pathology evolution. However, there are still technical limitations for separation and/or analysis of EVs, and in clinical practice, the standardization of EVs-based reproductible protocols is required urgently. Considering the presence of EVs in such a variety of body fluids and tissues, an important conclusion is to consider EVs both as biomarkers and potential therapeutic targets (especially for immunotherapies) and to exploit them in the next future to improve the outcome of cancer patients.
