PGR and Fibroadenoma: Moreover assessment of progesterone receptor expression, which is a favourable prognostic marker in uterine tumours,32, 33, 34, 35 revealed strong endometrial expression of progesterone receptor in uteri of Cdc73+/+ mice (Figure 5h), but absent endometrial progesterone receptor expression in all of the hyperplastic, fibroadenoma and adenomyoma lesions from Cdc73+/− mice (Figure 5i), which instead had increased stromal expression of progesterone receptor.