MME and metastatic neoplasm: Mechanistically, activation of SUV39H1 by the menin/Daxx complex increases transcriptionally repressive H3K9 trimethylation of the promoters of genes associated with neuroendocrine tumorigenesis [52,124], including the promoter of membrane metalloendopeptidase (Mme) [52], which is associated with larger, more proliferative, and metastatic tumors [52,124].