There are shards of evidence showing that changes in gonadotropin-releasing hormone (GnRH) secretion and gonadotropin ratios affect the gene expression of STAR (the steroidogenesis initiator) and CYP19A1 (an enzyme that converts testosterone to estradiol during steroidogenesis), resulting in an excess of androgen and hyperandrogenemia in PCOS [6]. Here, CYP19A1 is linked to polycystic ovary syndrome.