HSPG2 and polycystic ovary syndrome: In contrast, one study found that in patients with PCOS and normal ovulation, lower HSPG2 expression levels in CC were related to better-controlled ovarian hyperstimulation outcomes [33], and another study reported that lower HSPG2 expression in normo-ovulatory women was associated with more mature oocytes, transplantable embryos, and good quality embryos [32].