MYCN and neuroblastoma: PI3Kα inhibitor PIK-75 (78.9% cytotoxicity) stimulates anti-neuroblastoma activity by destabilizing MYCN and sensitizing tumor cells to anthracyclines (27, 60), and indeed increased cytotoxicity with PIK-75 was associated with PPM1D and GNA13 gain, and DNMT3A, CBL, EED and ASXL2 loss.