**6. Future perspectives**

EVs are endogenous carriers that facilitate intercellular communication. Although their existence has been known for a long time, they have attracted recent renewed interest because of their possible participation in the spread of particularly cancer initiating or metastasis promoting agents from tumour cells, which appear to produce them in excessive amounts. By the same token, EVs from normal cells may be able to reverse the malignant characteristics of cancer cells by transfer of tumour suppressors or pro-apoptotic molecules, providing more 'natural' therapy. In the drug delivery field, they are causing much excitement as potential therapeutics because of their efficient transfer of proteins, mRNA and miRNA, as well as existing drugs, into selective targets. They have obvious advantages over artificial liposomes or other nanoparticles. However, this requires more knowledge of EV content and how they are released, their stability and how they target cells. There is also a need for clearer quanti‐ tative and qualitative analysis of EVs in terms of their classification and production from normal and cancerous cells.
