MEN1 and pancreatic neuroendocrine tumor: Studies in sporadic NENs have reported few recurrently mutated genes: MEN1 (20%) and ARID1A (8%) in lung NETs [8], MEN1 (40%) and ATRX/DAXX (35%) in pancreatic NETs [9] and CDKN1B (10%) in small intestine NETs [10].