PDCD4 and glioblastoma: As well as an association with proliferation and differentiation, PDCD4 up-regulation has also been linked with senescence in human diploid fibroblasts (47), with serum withdrawal resulting in decreased PDCD4 expression in T98G glioblastoma cells (48) and translocation from the nucleus to the cytoplasm in NIH 3T3 fibroblasts (49).