In human leukemia cells, GDC-0152 downregulated cIAP1, cIAP2 and XIAP proteins and induced apoptosis through caspase-9 and -3 activation and inhibition of PI3K/Akt pathway.24 In human osteosarcoma, GDC-0152 attenuated the metastasis properties of the SaOS2 cell line via PI3K/Akt inhibition.25 We showed here that GDC-0152 increased apoptosis and differentiation in all GBM cell lines. Here, CASP9 is linked to osteosarcoma.