Figure 1 Biogenesis and secretion of exosomes and microvesicles Figure 1 | Biogenesis and secretion of exosomes and microvesicles. The maturation of early endosomal membranes into late endosomes involves formation of intraluminal vesicles that give rise to multivesicular bodies (MVB). These MVB can then translocate to the lysosome and deliver their cargo for degradation, and/or travel to, and fuse with, the plasma membrane to release vesicles called exosomes (size 20–140 nm) into the extracellular milieu. Conversely, microvesicles are formed by the outward budding of the plasma membrane and can range in size from 100 to 1000 nm in diameter. Mitochondria also produce microvesicle-like structures called mitochondrial-derived vesicles (MDV; size 70–150 nm). These MDV, once released from the mitochondria, can become part of the MVB and be transported to the lysosome for degradation, or secreted from the cell as exosomes. The biogenesis and secretion of exosomes and microvesicles is extensively reviewed elsewhere164. Permission obtained from Anusheh Saleem, Mississauga, Ontario, Canada. Permission obtained from Anusheh Saleem, Mississauga, Ontario, Canada. Safdar, A. et. al. (2016) The potential of endurance exercise-derived exosomes to treat metabolic diseases Nat. Rev. Endocrinol. doi:10.1038/nrendo.2016.76