As a type of secreted membrane vesicle, exosomes are emerging as an important mode of cell-to-cell communication. The objective of this study was to compare the abundance of mRNA and miRNA present in the parental B16F0 cell to mRNA and miRNA present in exosomes isolated from B16F0 conditioned media. Identifying local mechanisms of immunosuppression is a key barrier for expanding the clinical benefit of cancer immunotherapy. While exosomes are emerging as a new mode of intercellular communication, their role in establishing a malignant tissue niche remains unclear. Similar to the sculpting of tumor antigens during oncogenesis, a related hypothesis is that proteins secreted by malignant cells are shaped by somatic evolution. To test this hypothesis, we characterized the biological influence of tumor-derived exosomes on immune cell function. Overall design: 8 Total samples were analyzed. The abundance of miRNAs was estimated based on the average expression of all core probesets for a miRNA measured by Affymetrix microarray. The probability of a gene being expressed above background by random chance was estimated using the negative control probesets and a Welch's t-test, where the degrees of freedom were calculated using the Welch-Satterthwaite equation. A p-value of less than 0.01 was used for estimating the distribution of miRNA expression between cells and exosomes while a p-value of less than 1e-9 was used for qRT-PCR validation and pathway enrichment analysis. The lower p-value incorporates a Bonferroni correction for multiple hypothesis testing.