We observed that the mean value of OPN in overweight PCOS patients was significantly higher than that of lean PCOS patients (15.09 vs 10.31 ng/mL, P = 0.01, Fig. 1b), while there was no difference between lean control women and overweight control women (11.15 vs 12.81 ng/mL, P = 0.229, Fig. 1b). Here, SPP1 is linked to polycystic ovary syndrome.