**6. Conclusions**

The knowledge acquired studying EVs has allowed understanding that these particles are related to intercellular communication and cross-kingdom relationship. The release of these EVs by *Leishmania* is related to initial infection, modulation of the immune system, and disease progression in the host (**Table 1**). However, several aspects of the biology and physiology of these molecules still need to be better investigated. Would releasing these EVs into the vector be related to the parasite's adaptation to that environment? Can EVs contribute to parasite multiplication in the vector? Is there population regulation and/or transfer of resistance factors and immune response escape by EVs between different *Leishmania* species? Do these transfers occur in the vector and/or in the mammalian host? Can vesicles released by *Leishmania* be used for the development of vaccines and new diagnostic approaches? Thus, the field of EVs released by *Leishmania* and other pathogens is fascinating and, there will be significant advances and contributions to the area in the future with the discovery of new therapeutic targets and new players in the host–parasite relationship.


#### **Table 1.**

*Biological effects of the EVs released by different Leishmania species.*
