Histologically, we observed hyperplasia and adenomas in the pituitary glands, greatly enlarged follicles and corpora lutea in ovaries and uteruses in Cdkn1b-/- rats at 9 weeks of age, however, the thymus, spleen, and lung appeared histologically normal, despite the significantly increased organ size (S1G Fig). The gene discussed is CDKN1B; the disease is adenoma.