en Immunology Immunology Systematic Review <strong>Background: </strong>Exosomes are extracellular cells (EVs) emancipated by various cell types and are involved in cell-to-cell transmission. In cancer diseases, exosomes emerge as local and systemic cells to cell mediators of oncogenic information and play a significant role in the advancement of cancer through the horizontal transfer of various molecules, such as proteins and miRNAs.<br> &nbsp;&nbsp; <strong>Methods:</strong> In this study, 66 articles from PubMed, MEDLINE, Science Direct, Cochrane, EMBASE, and Scopus were used as English sources.<br> &nbsp;&nbsp; <strong>Results:</strong> The biological distribution of cancer cell-derived exosomes in tumor tissue is an important factor in detecting their role in tumor increase; on the other hand, a limited number of studies have examined the biodistribution of exosomes in tumor tissues. While exosomes function as cancer biomarkers and support cancer treatment, we have a long way to improve the antitumor treatment of exosomes and develop exosome-based cancer diagnostic and therapeutic strategies.&nbsp;<br> <strong>&nbsp;&nbsp; Conclusion: </strong>This review describes the science and significance of cancer pathogenesis and exosomes relative to cancer treatment resistance.<br> &nbsp; Exosome, Cancer pathogenesis, Tumor, Metastasis, Immune system 639 645 http://mjiri.iums.ac.ir/browse.php?a_code=A-10-5449-1&slc_lang=en&sid=1 Mehrdad Pashazadeh mehrdad_pashazadeh@yahoo.com 200319475328460064209 200319475328460064209 Yes Immunology Division, Department of Microbiology, Health Science Institute, Bursa Uludag University & Department of Immunology, Faculty of Medicine, Bursa Uludag University, Bursa, Turkey