HDACs/mTOR Inhibitor 1 is a dual Histone Deacetylases (HDACs) and mammalian target of Rapamycin (mTOR) target inhibitor for treating hematologic malignancies, with IC50s of 0.19 nM, 1.8 nM, 1.2 nM and >500 nM for HDAC1, HDAC6, mTOR and PI3Kα, respectively. HDACs/mTOR Inhibitor 1 stimulates cell cycle arrest in G0/G1 phase and induce tumor cell apoptosis with low toxicity in vivo.