Figure 2: Exosome biogenesis. Inward budding of endosomal membrane results in the formation of intracellular Multi-Vescular Bodies (MVBs), which will fuse with the plasma membrane and release the exosomes to the extracellular area. Exosomes can also be shed by outward budding of the plasma membrane or during cell apoptosis and necrosis, then entering the extracellular area. Exosomes then interact with target cells either by releasing its content (proteins, DNA, RNA, or even miRNA) or fusing with the plasma membrane [1,41].