EIF4EBP1 and pancreatic neuroendocrine tumor: The activation of the mTOR pathway in pancreatic endocrine tumors is also supported by immunohistochemical expression of p-mTOR [35], and its downstream effector eukaryotic translation initiation factor 4E binding protein 1 (p-4E-BP1) which has also been reported to be an independent factor of poor prognosis [36].