MMP2 and central nervous system cancer: Spearman’s rank correlation analysis revealed that the protein expression of ATF3 and MMP2 positively correlated with the pathological grade of glioma (ρ= 0.592, P<0.01 and ρ=0.726, P<0.01, respectively), while the protein expression of maspin negatively correlated with the pathological grade of glioma (ρ=−0.517, P<0.01).