Fig. 2

Exosome biogenesis and secretion within endosomal system by the endosomal sorting complex required for transport (ESCRT) pathway. Early endosomes (EEs) are formed by the fusion of endsomes. Subsequently, EEs depend on ESCRT to form multivesicular late endosomes (LEs)/bodies (MVBs). Rab27a and Rab27b direct the movement of LEs/MVBs toward the cell periphery, the SNARE complex helps LEs/MVBs fuse with the plasma membrane to release exosomes, and the rest of LEs/MVBs are degraded by lysosomes