Many of these models represent human syndromes e.g. MEN1 (Crabtree et al., 2001, Bertolino et al., 2003a, Biondi et al., 2002, Loffler et al., 2007a, Loffler et al., 2007b, Harding et al., 2009) and MEN4 (Kiyokawa et al., 1996, Nakayama et al., 1996, Fero et al., 1996), as well as representing a range of pituitary neoplasms that include hyperplasia, adenomas and carcinomas (Table 2). Here, CDKN1B is linked to pituitary tumor.