Fig. 1. Biogenesis of major extracellular vesicles classes. Apoptotic bodies are larger EVs (> 1 µm) formed during cellular death by apoptotic pathways. Microparticles (MPs) are sized ~100 - 1000 nm and released by membrane blebbing and shedding into the extracellular space. Exosomes are smaller (~40 - 100 nm), formed in a multi-step mechanism, with formation of multivesicular bodies (accumulation of intracellular vesicles) and posterior merge with the plasma membrane.