Melatonin was reported to inhibit the growth of estrogen receptors (ER) positive breast cancer such as MCF-7, T47D and ZR-75-1 cells more effectively than estrogen negative breast cancer cells such as BT-20, MDA-MB-231, MDA-MB-364, Hs587t, T47Dco [23, 24]. This evidence concerns the gene ESR1 and breast carcinoma.