A 2020 study was the first to investigate and show significantly higher levels of activating autoantibodies (AAbs) to the second extracellular loop (ECL2) of gonadotropin-releasing hormone receptor (GnRHR-ECL2-AAbs) in individuals with PCOS compared to both controls with ovulatory infertility and a group of healthy controls [13]. Here, GNRHR is linked to polycystic ovary syndrome.