Compared to other malignancies, PNETs tend to be well-differentiated indolent tumours, with >15% caused by germline mutations in the multiple endocrine neoplasia 1 (MEN1), Von Hippel–Lindau tumour-suppressor (VHL), TSC complex (TSC), neurofibromin 1(NF1), MutY DNA glycosylase, BRCA2 DNA repair-associated, cyclin-dependent kinase inhibitor 1B (CDKN1B), and checkpoint kinase 2 genes (Crona & Skogseid 2016, Scarpa et al. 2017). This evidence concerns the gene MEN1 and neoplasm.