PTGER3 and systemic lupus erythematosus: In order to further investigate the value of differently expressed EPs in predicting SLE risk, ROC curves were performed (Figure 5) and we found that EP1–4, EP6, and EP10 levels were all good predictors for SLE susceptibility with area under curve (AUC) as follows: EP1, AUC: 0.655, 95% CI 0.578–0.732; EP2, AUC: 0.618, 95% CI 0.538–0.698; EP3, AUC: 0.655, 95% CI 0.578–0.732; EP4, AUC: 0.878, 95% CI 0.830–0.926; EP6, AUC 0.749, 95% CI 0.678–0.820; EP10, AUC 0.590, 95% CI 0.501–0.680.