As pointed out above, 20–25% of ZES patients have it as part of the autosomal dominant disorder MEN1 [115,145,190], which is due to a mutation in the 10-exon MEN1 gene on chromosome 11q13, which encodes for a 610 amino acid protein, menin, which is a nuclear protein interacting with numerous transcription factors involved in genomic stability, transcriptional control, cell division, and cell cycle control [115,190]. This evidence concerns the gene MEN1 and Zollinger-Ellison syndrome.