Exosomes are small membrane vesicles secreted by most cell types and play important roles in intercellular communication. First discovered in 1983, exosomes were initially considered as cellular waste but have gained significant attention in recent years due to their ability to carry mRNA and microRNA, enabling them to transfer genetic information between cells. This has sparked renewed interest in exosomes and other secreted membrane vesicles, leading to exponential growth in research over the past few years. Exosomes are formed within endosomal compartments called multivesicular endosomes and are released when these compartments fuse with the plasma membrane. They contain proteins, lipids, and nucleic acids and can influence the function and physiology of recipient cells. Exosomes are now known to be secreted by various cell types, including immune cells, and have been shown to play roles in immune responses, tumor biology, and other physiological processes. Research has shown that exosomes can carry antigens and MHC-peptide complexes, which can activate immune responses or induce tolerance. They also contain RNA and microRNA, which can be translated into proteins in target cells, suggesting they can transfer genetic information. However, the physiological functions of exosomes in vivo are still not fully understood, and further research is needed to determine their exact roles. Exosomes are similar in size to other secreted membrane vesicles, such as ectosomes and microvesicles, but differ in their origin and composition. While exosomes are formed within endosomal compartments, other vesicles bud directly from the plasma membrane. The distinction between these vesicles is still a topic of debate, and more research is needed to clarify their roles. The field of exosome research has grown rapidly, with numerous studies exploring their potential as biomarkers and therapeutic tools. The International Workshop on Exosomes (IWE) has played a key role in advancing this field, bringing together researchers to discuss the latest findings and future directions. The IWE has led to the establishment of a scientific society dedicated to exosomes and secreted membrane vesicles, as well as the development of databases and virtual spaces for collaboration. In conclusion, exosomes are important secreted membrane vesicles that play a role in intercellular communication and have potential applications in medicine. However, much remains to be discovered about their physiological functions and the mechanisms underlying their secretion. Continued research is essential to fully understand their roles in health and disease.Exosomes are small membrane vesicles secreted by most cell types and play important roles in intercellular communication. First discovered in 1983, exosomes were initially considered as cellular waste but have gained significant attention in recent years due to their ability to carry mRNA and microRNA, enabling them to transfer genetic information between cells. This has sparked renewed interest in exosomes and other secreted membrane vesicles, leading to exponential growth in research over the past few years. Exosomes are formed within endosomal compartments called multivesicular endosomes and are released when these compartments fuse with the plasma membrane. They contain proteins, lipids, and nucleic acids and can influence the function and physiology of recipient cells. Exosomes are now known to be secreted by various cell types, including immune cells, and have been shown to play roles in immune responses, tumor biology, and other physiological processes. Research has shown that exosomes can carry antigens and MHC-peptide complexes, which can activate immune responses or induce tolerance. They also contain RNA and microRNA, which can be translated into proteins in target cells, suggesting they can transfer genetic information. However, the physiological functions of exosomes in vivo are still not fully understood, and further research is needed to determine their exact roles. Exosomes are similar in size to other secreted membrane vesicles, such as ectosomes and microvesicles, but differ in their origin and composition. While exosomes are formed within endosomal compartments, other vesicles bud directly from the plasma membrane. The distinction between these vesicles is still a topic of debate, and more research is needed to clarify their roles. The field of exosome research has grown rapidly, with numerous studies exploring their potential as biomarkers and therapeutic tools. The International Workshop on Exosomes (IWE) has played a key role in advancing this field, bringing together researchers to discuss the latest findings and future directions. The IWE has led to the establishment of a scientific society dedicated to exosomes and secreted membrane vesicles, as well as the development of databases and virtual spaces for collaboration. In conclusion, exosomes are important secreted membrane vesicles that play a role in intercellular communication and have potential applications in medicine. However, much remains to be discovered about their physiological functions and the mechanisms underlying their secretion. Continued research is essential to fully understand their roles in health and disease.