Six different mouse models for MEN1 have been generated, consisting of 4 conventional heterozygous and 2 conditional homozygous Men1 knockouts, and 5 of these 6 models develop pituitary adenomas (Crabtree et al., 2001, Bertolino et al., 2003a, Bertolino et al., 2003b, Biondi et al., 2002, Loffler et al., 2007a, Loffler et al., 2007b, Harding et al., 2009, Biondi et al., 2004, Crabtree et al., 2003). The gene discussed is MEN1; the disease is pituitary gland adenoma.