ESR1 and Uterine leiomyoma: It is well known that uterine leiomyomas are estrogen-dependent, with higher estrogen receptors than surrounding normal tissues.[17] Increased proliferation of uterine fibroids was observed in vitro when exposed to estradiol and progesterone.[18] For patients who have undergone hysteromyomectomy, strict contraception is required for a period of time.