These included 76 (54%) nonfunctioning pNENs and 64 (46%) functioning pNENs (30 insulinomas, 24 gastrinomas, 10 rare pNENs), which were sporadic in 94 (67%) cases and associated with MEN1 (Multiple Endocrine Neoplasia 1) in 46 (33%) cases. This evidence concerns the gene MEN1 and gastrin-producing neuroendocrine tumor.