ESR1 and breast carcinoma: Some compounds have presented antitumor activity, such as annonacin (an acetogenin), which induced growth arrest and apoptosis in estrogen receptors alpha (ERα) in MCF-7 breast cancer cells, and further attenuated MCF-7 xenograft tumor growth by inhibiting ERα expression, cyclin D1 and Bcl-2 in mice [10].