MMP9 and central nervous system cancer: In the low grading gliomas, quantitative analysis revealed the mean expression levels of MMP-2 and MMP-9 staining were 16.38±8.43% and 12.09±7.98%, respectively, compared to those of 60.47±21.45% and 41.03±14.00% in the high grading gliomas (Table 1).