Ectosomes and exosomes: shedding the confusion between extracellular vesicles

•The characteristics and mechanisms of ectosomes and exosomes are defined.•Exosomes are released on the exocytosis of MVBs, whereas ectosomes are assembled and released from the plasma membrane.•Interactions of vesicles with target cells and vesicle navigation are illustrated.•The role of vesicles in cancer diagnosis and therapy is discussed.

Long- and short-distance communication can take multiple forms. Among them are exosomes and ectosomes, extracellular vesicles (EVs) released from the cell to deliver signals to target cells. While most of our understanding of how these vesicles are assembled and work comes from mechanistic studies performed on exosomes, recent studies have begun to shift their focus to ectosomes. Unlike exosomes, which are released on the exocytosis of multivesicular bodies (MVBs), ectosomes are ubiquitous vesicles assembled at and released from the plasma membrane. Here we review the similarities and differences between these two classes of vesicle, suggesting that, despite their considerable differences, the functions of ectosomes may be largely analogous to those of exosomes. Both vesicles appear to be promising targets in the diagnosis and therapy of diseases, especially cancer.