ESR1 and ovarian cancer: In ovarian cancer, the effect of the pineal hormone on the ERα levels remains unexplored, although it is known that melatonin (100 μg/100 g of body weight/day, 150 days) decreases estradiol, increases progesterone, and downregulates androgen receptor, ERα, and ERβ levels in oviducts and uteri of rats [143].