CPEB3 and central nervous system cancer: In order to understand why CPEB3 protein is strongly expressed but not activated/phosphorylated in high-grade gliomas, we decided to further examine tumors with strong (intensity 3) phospho-CPEB3 expression (n = 6, AII and AAIII) and samples negative for phospho-CPEB3 (n = 7, pGBM).