Intriguingly, in glioma-bearing rats, FTY720 can internalize CXCR4 on glioma-associated microglia and macrophages in the tumor microenvironment to suppress the migration/invasion of C6 glioma cells by preventing MAPK-mediated IL-6 release [135] (Figure 4). The gene discussed is CXCR4; the disease is glioma.