The present invention relates to the use of antagonists of the mTOR signaling pathway and its constituent members (e.g., antagonists of MAPKAP) for the treatment, amelioration, and diagnosis of PI3K/AKT/mTOR-related disorders, e.g., cancers. The present invention also relates to methods of using modulators of mTOR (e.g., modulators of MAPKAP) for the treatment, amelioration, and diagnosis of PI3K/AKT/mTOR-related disorders, e.g., cancers. Assays for the identification of modulators of mTOR, MAPKAP, and hVPS34 are also provided.