Extracellular vesicles and viruses: Are they close relatives? (pnas.org) Extracellular vesicles and viruses: Are they close relatives? Esther Nolte-‘t Hoena , Tom Cremera , Robert C. Gallob,1, and Leonid B. Margolisc Edited by Peter K. Vogt, The Scripps Research Institute, La Jolla, CA, and approved June 27, 2016 (received for review April 4, 2016) Extracellular vesicles (EVs) released by various cells are small phospholipid membrane-enclosed entities that can carry miRNA. They are now central to research in many fields of biology because they seem to constitute a new system of cell–cell communication. Physical and chemical characteristics of many EVs, as well as their biogenesis pathways, resemble those of retroviruses. Moreover, EVs generated by virus-infected cells can incorporate viral proteins and fragments of viral RNA, being thus indistinguishable from defective (noninfectious) retroviruses. EVs, depending on the proteins and genetic material incorporated in them, p...