In Nano-DOX-BMDM-treated mice, Nano-DOX can be delivered to GBM via GBM-associated immune cells (e.g., macrophages) to inhibit STAT3 activation in glioma cells and reduce their export of IL-6 to astrocytes, thereby abolishing feedback activation of astrocytes to glioma cells (Chen et al., 2020b). Here, IL6 is linked to central nervous system cancer.