ESR2 and neoplasm: That was consistent with various studies that demonstrated the anti-proliferative effect of ERβ in MDA-MB-231 and MDA-MB-468 TNBC cell lines after ERβ exogenous expression and its activation by E2 or specific agonists such as DPN, which was able to notably inhibit TNBC cell growth, arrest cell cycle at the G1 phase, block cell colony formation, inhibit cell invasiveness and reduce tumor size in mice xenografts [11, 46].