MMP2 and central nervous system cancer: Membrane type 1 metalloprotease (MT1-MMP), matrix metalloproteinase-2 (MMP2), cathepsin B, and urokinase receptor (uPAR) are overexpressed in gliomas and they are postulated to play central roles in breaking down the extracellular matrix in the tumor area and, thereby, creating pathways for tumor cells invasion [7, 8, 19, 20].