MMP9 and glioma: Important factors expressed by TAMs in gliomas include TNF-ß, high levels of interleukins 6 and 10 (Il-6, Il-10), MMP2 and MMP9, and VEGF and VEGA, which collectively promote glioma proliferation and invasion, angiogenesis and suppression of T effector cell and NK cell activity [2,38,40,51,52].