Tehran University of Medical Sciences Immunology and Genetics Journal 2645-4831 6 1 2023 03 22 1 5 Mohaddese Pourashoury Islamic Azad University, Garmsar Branch, Semnan, Iran 2023 03 14 2023 03 14 Exosomes are tiny vesicles that cells secrete into the extracellular environment. They are crucial in cellular communication and have wide-ranging physiological and pathological ramifications. Cargo sorting, MVB development and maturation, MVB transport, and MVB fusion with the plasma membrane are the four essential steps in exosome biogenesis. The high heterogeneity of exosomes is due to the fact that each process is modulated by the competition or coordination of multiple mechanisms, resulting in the sorting of diverse compositions of molecular cargos into different subpopulations of exosomes. In cancer, exosomes have been shown to play a crucial role in tumor growth, metastasis, and pre-metastatic niche formation. In this mini-review, we briefly compile what we know about exosomes at present, including how they are made, what they carry, and how they promote tumor growth. Exosomes' potential as diagnostic and prognostic biomarkers is discussed. We also take a look at the research that hasn't been done and the challenges that have been overlooked. https://igj.tums.ac.ir/index.php/igj/article/view/129 https://igj.tums.ac.ir/index.php/igj/article/download/129/114