Figure 1.

Biogenesis of extracellular vesicles. (a) Exosomes are formed by invagination of the endosomal membrane to form early endosomes. A second inward budding process leads to the formation of multivesicular bodies (MVBs). These are sorted to fuse either with lysosomes, leading to degradation, or with the plasma membrane, releasing their contents as exosomes. (b) Microvesicles are formed by the direct outward budding of the plasma membrane. (c) Apoptotic bodies are formed during the disintegration of the plasma membrane in dying cells. Figure created using biorender.com.