MMP9 and central nervous system cancer: As shown in Figure 6D, the protein levels of TREM2, anti-apoptosis (Bcl2), invasion (MMP2 and MMP9) and chemokine pathway related factors (CXCL10 and CXCR3) were significantly higher in glioma tissues than in normal tissues, while the expression of apoptosis-related factors (cleaved caspase 3 and Bad) was remarkably lower in glioma tissues.