Figure 1.

The biogenesis and structure of exosomes. The biogenesis of exosomes initiates with the inward budding of the plasma membrane, resulting in the creation of early sorting endosomes (ESEs), which may subsequently mature into LEs and MVBs. MVBs can either fuse with lysosomes for degradation or convey ILVs to the plasma membrane, releasing them into the extracellular space, thus forming exosomes. Exosomes are lipid membrane-enclosed extracellular structures, which include a variety of cellular proteins, lipids, DNAs, and RNAs with diverse biological functions.