MMP9 and central nervous system cancer: Sixty glioma-associated targets were associated with CHR, such as MDR transporters (ABCB1, ABCC1, ABCG2), cyclin-dependent kinases (CDK1, CDK6), matrix metalloproteinases (MMP2, MMP9, MMP12), and genes related to inflammation or oxidative stress (NOS2, NOX4) (Levicar et al., 2003; Agarwal et al., 2010; Gialeli et al., 2011).