Comprehensive evaluation of the compounds’ performance across both AC/MN and SC/schwannoma assay systems in vitro with the goal of selecting drugs that had the highest likelihood of efficacy against both tumor types in vivo resulted in three compounds being selected to be advanced to in vivo testing: CUDC-907 (dual PI3K/HDAC inhibitor), Panobinostat (HDAC inhibitor), and GSK2126458 (dual PI3K/mTOR inhibitor). This evidence concerns the gene HDAC9 and neoplasm.