ESR1 and breast carcinoma: Furthermore, when a physiological level of estrogen is combined with progesterone (e.g., combined HRT) or an androgen (e.g., estrogen plus Adiol in the early menopausal transition), the combination of those hormones would result in replacement of the DREAM complex by pro-proliferative MuvB-FOXM1 and MuvB-MYBL2 complexes (Figure 6b), leading to an increase in ER+ breast cancer.