MDM2 and glioblastoma: The array-based comparative genomic hybridization revealed that murine double minute 2 (MDM2) overexpression, a RING finger E3 ubiquitin ligase, is observed in glioblastoma, which is caused by amplification of the MDM2 gene, located on chromosome 12 (12q14–15).41 Since the MDM2 can reduce the level and activity of p53, one of the most important tumor suppressors, the mutational inactivation of MDM2 could contribute to glioblastoma development.