In this study, we found that glioma-associated mesenchymal stem cells (GA-MSCs) promoted glioma progression by upregulating CD73 expression on MDSCs through exosomal miR-21, which was similar to our previously reported finding that glioma-derived exosomal miR-21 promotes MDSC activation [35], but more intense. This evidence concerns the gene NT5E and central nervous system cancer.