Menin, the gene product of MEN1, is a predominantly nuclear protein that functions as a tumor suppressor by i) interacting with various transcription factors and histone modification enzymes to regulate gene transcription, ii) regulating cell cycle progression (via upregulation of CDKN2C/CDKN1B expression), and iii) participating in specific cell signaling processes (for example, menin alters AKT1 sub-cellular localization to regulate the PI3K/AKT/mTOR signaling pathway) (26). This evidence concerns the gene MEN1 and neoplasm.