Since it is possible to boost anticancer effects of HDACIs by selective targeting of the PI3K/Akt pathway, the effect of PI3K, Akt, and dual PI3K/mTOR inhibitors either alone or in combination on the therapeutic potential of HDACIs in HNSCC cell lines and xenograft HNSCC models was investigated [157]. This evidence concerns the gene MTOR and head and neck squamous cell carcinoma.