Fig. 1. The biogenesis, secretion, and uptake of tumor-derived exosomes.

Firstly, the endocytosis results in the formation of early endosomes. Then, the endosomes and selected cargos including nucleic acids, proteins, and lipids are encapsulated into multivesicular bodies (MVBs). Finally, these MVBs fuse with the plasma membrane and release exosomes into extracellular place. The release of exosomal contents (proteins, mRNAs, miRNAs, lncRNAs, circRNAs, and DNAs) to the recipient cells via direct cell membrane fusion, receptor interaction, and endocytosis. noncoding RNA ncRNA, microRNA miRNA, long noncoding RNA lncRNA, circular RNA circRNA, major histocompatibility complex MHC, epidermal growth factor receptor EGFR, late multivesicular body MVB.