For example, exosomal miR-34c inhibits β-catenin signaling and epithelial – mesenchymal transition, thereby enhancing apoptosis and increasing radiosensitivity in nasopharyngeal carcinoma cells.16,17 Nonetheless, certain ADSC-derived exosomes, such as those containing miR-21, may contribute to tumor progression by downregulating PTEN expression and promoting macrophage polarization toward tumor-associated phenotypes.18 This evidence concerns the gene PTEN and neoplasm.