Clinical genetic studies have identified that gastrointestinal (small intestine) NETs can have somatic mutations in MEN1, CDKN1B, and other genes involved in the PI3K/AKT/mTOR signaling pathway (43–45) and more recent whole-exome sequencing data have identified that 14% of pancreatic neuroendocrine tumors (NETs) have mutations in genes of the mTOR signaling pathway (46). Here, MEN1 is linked to pancreatic neuroendocrine tumor.