MEN1 is a tumor suppressor gene located on chromosome 11 [37] encoding for the protein Menin, which is an important factor for the regulation of chromatin remodeling [38–40] and seems to play a key role in tumor initiation as MEN1 alterations are already detectable in pancreatic microtumors [41] and as germline mutation in the genetic syndrome multiple endocrine neoplasia type 1 (MEN1, see below). This evidence concerns the gene MEN1 and neoplasm.