CD4 and neoplasm: The results showed that compared to miR-17-5p-NC-Exo-treated nude mice, CRCSC-exos upregulating miR-17-5p treatment increased tumor volume and weight, reduced serum contents of TNF-α and IL-2, and relieved the CD4+ and CD8+ T cell infiltration, yet facilitated the inflammatory infiltration and promoted serum contents of IL-10 and TGF-β; the exosomes silencing miR-17-5p treatment exerted contrary effects (Fig. 5A–F).