Indolent insulinomas usually present as small lesions (<3 cm), become symptomatic with hypoglycemia early, and exhibit a genetic and epigenetic signature close to their presumed cell of origin, the β-cell, due to expression of pancreatic and duodenal homeobox 1 (PDX1) and glucagon-like peptide-1 receptor (GLP-1R) (Di Domenico et al. 2020, Hackeng et al. 2020, 2023, Rindi et al. 2022). This evidence concerns the gene PDX1 and pancreatic insulinoma.