Conditional inactivation of the MEN1 gene leads to pancreatic and pituitary tumorigenesis but does not affect normal development of these tissues. - Biondi,C.A.; Gartside,M.G.; Waring,P.; Loffler,K.A.; Stark,M.S.; Magnuson,M.A.; Kay,G.F.; Hayward,N.K. (Mol Cell Biol, 2004)