Irradiation-enhanced MMP2 promoter activity, mRNA transcription, and protein secretion associated with invasiveness was observed in glioma cells lacking functional PTEN (U87, U251, U373, and C6) but not in those harboring wild-type PTEN (LN18 and LN428) (Park et al., 2006a; Cordes et al., 2003). This evidence concerns the gene MMP2 and central nervous system cancer.