MEN1 Full-Length MS Protein Standard (NP_570711), Labeled with [U- 13C6, 15N4]-L-Arginine and [U- 13C6, 15N2]-L-Lysine, was produced in human 293 cells (HEK293) with fully chemically defined cell culture medium to obtain incorporation efficiency at Creative-Proteomics. This gene encodes menin, a putative tumor suppressor associated with a syndrome known as multiple endocrine neoplasia type 1. In vitro studies have shown menin is localized to the nucleus, possesses two functional nuclear localization signals, and inhibits transcriptional activation by JunD, however, the function of this protein is not known. Two messages have been detected on northern blots but the larger message has not been characterized. Alternative splicing results in multiple transcript variants.