ESR2 and neoplasm: However, it remains to be examined whether the type of endocrine intervention in TNBC should be based on E2 treatment to activate the tumor-suppressing functions of ERβ, or on the use of antiestrogens or aromatase inhibitors, since single studies reported faslodex to have potent growth-inhibitory effects on ERβ-positive TNBC and tamoxifen to exert beneficial actions in ERβ-positive TNBC with mutant TP53 [39,45].