PIK3CA and neuroblastoma: Although Torin1, an ATP-competitive mTOR inhibitor [16] with preferential activity against mTOR (EC50, 3 nM) compared to PI3K (EC50, 1.8 μM), exhibited impressive cytotoxicity with downregulation of mTORC1 and mTORC2 targets in Kelly NB cells (Supplementary Fig. S1A and B), it has a low-yielding synthetic route, poor water solubility, limited oral bioavailability and a short half-life.