Fig. 1

Biogenesis of exosomes (Exos). The endosomal system is actively involved in the generation of Exos. The internalized Exos are sorted into early endosomes. In the next steps, these endosomes mature into late endosomes and MVBs where new nano-sized vesicles, ILVs, are generated via the invagination of the endosomal membrane. These particles are named Exos upon their release into the ECM. MVBs can direct lysosomal degradation to directly fuse with the cell membrane to release their contents into the ECM. Abbreviations: MHC1: major histocompatibility complex 1, CD: Cluster of differentiation, EGFR: Epidermal Growth Factor Receptor, HSP: Heat shock proteins, HIF-1α: Hypoxia-inducible Factor 1α, GAPDH: Glyceraldehyde-3-phosphate dehydrogenase, TSG101: Tumor susceptibility gene 101, ARF-1: ADP-ribosylation factor 1, PI3K: Phosphoinositide 3-kinases, Rab: Ras-associated binding, SNARE: soluble N- ethylmaleimide- sensitive fusion attachment protein receptor, MVB: Multivesicular Body, ESCRT: Endosomal sorting complexes required for transport, STAM: Signaling transducing adaptor molecule, VPS4: Vacuolar protein sorting 4, ALIX: ALG-2-interacting protein X