Fig. 1

Biogenesis, content, and surface marker profile of small extracellular vesicles. A Ectosomes are shed from the plasma membrane by outward budding; B (1) Intraluminal vesicles form within endosomes by invagination of the endosomal membrane. Multivesicular bodies (2) fuse with lysosomes to undergo degradation or (3) are directed to the plasma membrane along microtubules. (4) Multivesicular bodies dock at the plasma membrane. (5) Intraluminal vesicles are released into the extracellular space as exosomes upon fusion of multivesicular bodies with the plasma membrane; C Content and surface markers of small extracellular vesicles. BSG/SLC3A2 and LAMP1 might represent specific markers for small ectosomes and exosomes, respectively