PIK3CB and neoplasm: Targeting the PI3K/Akt/mTOR pathway could also be combined with more traditional treatment modalities in pituitary tumors, potentially increasing efficacy and/or reducing toxicity by allowing dose reduction: mTOR inhibitors increase radiosensitivity of pituitary tumor cells in vitro (115), and temozolomide and XL765 (a dual PI3K/mTOR inhibitor) synergistically inhibit cellular proliferation in vitro and reduce tumor growth and hormone secretion in xenograft mice (116).