MTOR and pituitary tumor: Unfortunately, in vitro data demonstrating upregulation of PI3K/AKT/mTOR pathways in pituitary tumors have so far not translated into clinical success in aggressive pituitary tumors, apart from a single case report of a partial response to everolimus in an aggressive prolactinoma, where the patient achieved stability of tumor volume for 12 months and a decrease in prolactin levels [135].