“…T47D human breast cancer cells, which naturally express both human estrogen receptor (ER)-α and -β, were transferred with an estrogen-responsive element luciferase reporter gene construct [5]. The 17-β estradiol (E 2 ) agonist positive control is a natural steroid sex hormone produced by the ovaries named according to UIPAC as (8R,9S, 13S, 14S, 17S)-13-methyl-6,7,8,9,11,12,14,15,16,17-decahydrocyclopenta[a]phenanthrene-3,17-diol [1], with molecular mass of 272.388 g/mol. The antagonist ICI 182,780 is a synthetic steroidal antiestrogen derived from E 2 named by IUPAC as (7R, 8R, 9S, 13S, 14S, 17S)-13-methyl-7-[9-(4,4,5,5,5-pentafluoropentylsulfinyl)nonyl]-6,7,8,9,11,12,14,15, 16,17-decahydrocyclopenta[a]phenanthrene-3,17-diol [1], with a molecular mass of 606.777 g/mol.…”