The results showed that the serum levels of PD-1 (Figure 2(a)) and PD-L1 (Figure 2(b)) in patients with PCOS were 0.76 ± 0.03 ng/mL and 1.41 ± 0.04 ng/mL, which were significantly lower than those in the control group (1.19 ± 0.03 ng/mL and 1.93 ± 0.04 ng/mL, respectively) (P < 0.01), suggesting that abnormalities of PD-1 and PD-L1 in the serum of PCOS patients may be related to the onset of PCOS. The gene discussed is PDCD1; the disease is polycystic ovary syndrome.