M2 macrophages may promote tumor progression and poor prognosis by inhibiting CD8+ T cell function (27).Numerous studies have shown that various chemokines, including CCL2, CXCL12, LOX, MCP-3, and M-CSF, are secreted by glioma cells to attract M2 macrophages and change their phenotypes (28). Here, CXCL12 is linked to central nervous system cancer.