Mann–Whitney test was performed to compare FSH, LH, DHEA, progesterone and oestradiol levels between two groups: (1) the PCOS group and the fertile group, (2) the obese PCOS group and the non-obese PCOS group and (3) the obese group and the non-obese fertile group. Here, PLOD1 is linked to polycystic ovary syndrome.