Interestingly, the RASSF1A gene promoter was also shown to be hypermethylated in about 98% of MEN1 neuroendocrine tumors of the pancreas [11], suggesting the epigenetic inactivation of this gene as a common pathway of MEN1 loss-driven tumorigenesis in target endocrine tissues. This evidence concerns the gene MEN1 and pancreatic neuroendocrine tumor.