The Genetics and Endocrinology Section studies the genetic bases of primary hyperparathyroidism and its relations to other neoplastic disorders. We have cloned the gene for multiple endocrine neoplasia type 1 and found that it is implicated in many nonhereditary tumors. This tumor suppressor gene encodes a novel protein, menin. We are studying the actions of menin protein by yeast two-hybrid, microarray, knockout, and other approaches. We have identified an important interaction of menin with junD, a nuclear transcription factor.