Similarly, increased angiogenesis has been observed in glioma model mice, in which the COX-2 and CCL2 pathways promote gliomagenesis by directly supporting the systemic development of myeloid-derived suppressor cells (MDSC) and their accumulation in the tumor microenvironment, where they limit cytotoxic T lymphocyte infiltration [54]. Here, CCL2 is linked to glioma.