 Tumor metastasis is a hallmark of colorectal cancer, CRC, in which exosomes play a crucial role with their function in intercellular communication. Exosomes were collected from healthy control, HC, donors, localized primary CRC and liver metastatic CRC patients. We performed proximity barcoding assay, PBA, for single exosome analysis, which enabled us to identify the alteration in exosome subpopulations associated with CRC progression. By in vitro and in vivo experiments, the biological impact of these subpopulations on cancer proliferation, migration, invasion, and metastasis was investigated. 12 distinct exosome subpopulations were determined. We found two distinctly abundant subpopulations, one ITGB3 positive and the other ITGM positive. The ITGB3 positive cluster is rich in liver metastatic CRC, compared to both HC group and primary CRC group. On the contrary, ITGM positive exosomes show a large-scale increase in plasma of HC group, compared to both. This article was authored by Weiguo, Yanling Kai, Xianming Liu, and others. We are article.tv, links in the description below.