The Rotterdam Criteria does not include the LH/FSH ratio as one of the diagnostic criteria for PCOS, but the Reproductive Endocrine Committee of the Japanese Obstetrics and Gynecology Association regards LH/FSH ≥ 1 as an important indicator for the diagnosis of PCOS (Hendriks et al., 2008). Here, PLOD1 is linked to polycystic ovary syndrome.