MEN1 and pituitary tumor: The frequency of pituitary tumour development in female 129S6/SvEv Men1+/- mice over 12 months of age in our study was consistent with that of another 129S6/SvEv model (29) (38% vs 32%, respectively), while the significantly increased frequency of pituitary tumours in female C57BL/6 Men1+/- mice (75.7%) is consistent with a previous C57BL/6 mouse study (77.8%) (30).