GADD45B and glioblastoma: These results collectively confirmed that PBI-05204–induced apoptotic cell death is mediated by activation of caspases in GBM cells. Furthermore, PBI-05204–treated U87 cells had less abundant of NF-κB p65 and Gadd45β, markers important in cell cycle and apoptosis (Bernal-Mizrachi et al., 2006; Tamura et al., 2012), than that of control vehicle treated cells (Supplemental Figure 1).