ESR1 and polycystic ovary syndrome: It has been reported that the endometrium from PCOS-like rodents and patients with PCOS is morphologically normal, but exhibits structurally and biochemically abnormal responses to hormone stimulation; uterine E2-regulated glycolysis via ERα activation may contribute to successful implantation and the establishment of pregnancy, as E2 is widely regarded as a master regulator of endometrial cell proliferation (86, 87).