Fig. 1
From: The role and application of small extracellular vesicles in gastric cancer
The biogenesis and compositions of exosomes. Golgi apparatus could produce lipid rafts, which facilitate endocytosis. Early endosomes (EE) are formed after the inward budding of the plasma membrane, then they transport from early to late endosomes (LE), which transforming into multivesicular bodies (MVBs) when membrane vesicles sprout inward the cavity. Secretion or degradation is under control of ESCRT family and ESCRT-independent RAB31. Cholesterol-rich (CHL-R) and RAB31-high pre-exosomes are destined to secreted as exosomes, while cholesterol deficient (CHL-D) and RAB31-low are degraded. Exosomes contain complex contents such as proteins, mRNA, miRNA, lncRNA, and DNA. Some protein biomarkers are used to characterize exosomes currently