MEN1 and pancreatic neuroendocrine tumor: Furthermore, overexpression of menin in the human endocrine pancreatic tumor cell line (BONI) resulted in an inhibition of cell growth (Stalberg et al., 2004) that was accompanied by upregulation of JunD expression but downregulation of δ-like protein 1/preadipocyte factor-1, proliferating cell nuclear antigen, and QM/Jif-1, which is a negative regulator of C-Jun (Stalberg et al., 2004).