MEN1 and pancreatic insulinoma: Insulinoma showed a major rate of hypermethylation among the other subgroups of functioning PanNENs, especially in epigenetic modifying enzymes as INS/IGF2 locus, CDNK1C, MEN1, KDM6A, MLL3/KMT2C, YY1, KDM5B, and SMARCC1 [114,115].