The receiver operating characteristic (ROC) analysis demonstrated that leptin had the highest diagnostic accuracy for distinguishing obese and non-obese PCOS patients, with an AUC of 0.85 (95% CI: 0.79-0.91, p<0.001), a sensitivity of 82.5%, and a specificity of 78.7% at a cut-off value of 19.2 ng/mL. The gene discussed is LEP; the disease is polycystic ovary syndrome.