HOXA10 and polycystic ovary syndrome: Sufficient pituitary downregulation improves endometrial receptivity in patients with PCOS, whose receptivity is poor because of basic endocrine and metabolic disorders.[62] Another study found that the content of HOXA10 in endometrial stromal cells, which is closely related to embryo implantation, was significantly lower in patients treated with the antagonist protocol than in those treated with the long protocol.