CDKN1B and pituitary gland adenoma: TRβPV/PV mice possess a knock-in mutation of the TRβ gene and spontaneously develop TSH-secreting pituitary adenomas (TSHoma) with age (102); MENX rats harbor biallelic frameshift mutations of the CDKN1B gene (encoding p27KIP1) and develop pituitary adenomas alongside multiple other endocrine tumors (103).