PLOD1 and polycystic ovary syndrome: Women with PCOS generally have elevated gonadotropin-releasing hormone (GnRH) pulsatile activity, high levels of luteinizing hormone (LH), hyperactivity of theca-stromal cell and altered activity of granulosa cell that causes reduced production of estradiol (E2) and progesterone (P4) by pre-ovulatory follicle [29, 30].