Figure 1.

Biogenesis of EV and their main components. Exosomes (50-150 nm) primarily originated from the endosomal membrane system. Invagination of the plasma membrane led to the formation of early endosomes. Then, endosomes are either destined to degrade in lysosomes or to mature into late endosomes and subsequently released into the circulation. Microvesicles (100-1000 nm) are formed by outward cell membrane budding, which is triggered by various cell states. Some cargos could be recruited into either exosomes or microvesicles during the processes. Oncosomes (100-400 nm) and large oncosomes (1-10 μm) are triggered by specific mechanisms only in cancer cells. ESCRT, endosomal sorting complex required for transport; TSG101, tumor susceptibility gene 101; CD, cluster of differentiate; PLD, phospholipase D; ERK, extracellular signalregulated kinases; MLC, myosin light chain; MLCK, myosin light chain kinases; EGFR, epidermal growth factor receptor; Akt, protein kinase B; DIAHP3, diaphanous related formin 3.