We previously reported that CEP-1347 exerted p53-activating and tumor growth-inhibiting effects by acting as an MDM4 inhibitor in the GBM and MM cell lines used in the present study as well as in retinoblastoma and uveal melanoma cell lines, all of which have wild-type p53 [23,24,29,30]. The gene discussed is TP53; the disease is glioblastoma.