These controversies have developed primarily because of the uncertain role of surgery (both timing and type) in the management of both gastrinomas and small, NF-pNET, (<1.5–2 cm) in MEN1/ZES patients, or MEN1 patients in general, which was discussed above in Section Controversy of the Role of Specific NET Imaging Studies in ZES/NET/pNET Diagnosis. This evidence concerns the gene MEN1 and gastrin-producing neuroendocrine tumor.