NSC 781406 is a dual inhibitor of PI3K and mTOR, exhibiting potent activity against various PI3K isoforms (IC50s ranging from 2.0 to 14 nM) and mTOR (IC50 = 5.4 nM). It suppresses cell growth in the NCI-60 cancer cell panel (mean GI50 = 65 nM) and demonstrates anti-tumor effects in a BEL-7404 hepatic cancer mouse model (30 mg/kg).