外泌体是一种直径为30～100 nm，主要由细胞内多泡体与细胞膜融合并释放到细胞外基质中的膜囊泡，可携带核酸、蛋白质等分子，具有强大的生物学功能。本文系统阐述了外泌体的发现历程、主要功能，及其在肿瘤生长、转移、免疫逃逸、诊断、治疗和在动脉粥样硬化、心肌梗死、心室重构、心脏再生等多种心血管生理和病理过程中的调控作用。总而言之，外泌体这个小小囊泡中蕴藏着大学问。

Exosomes are endosomes derived extracellular vesicles of 30～100 nm size range, which carry nucleic acid and protein. Exosomes have powerful biological functions. Here we described the discovery and functions of exosomes. In addition, we also summarized the roles of exosomes in cancer growth, metastasis, immune escape, diagnosis, and treatment. Besides, functions of exosomes in a variety of cardiovascular physiological and pathological processes including atherosclerosis, myocardial infarction, ventricular remodeling, and cardiac regeneration are reported. In summary, a big knowledge is contained in these small vesicles.