S100A8 and Sepsis: A receiver operating characteristic (ROC) curve analysis was then conducted to determine the accuracy of these seven genes in diagnosing sepsis: S100A8 showed very high accuracy (i.e., area under the curve (AUC): 0.931, 95% confidence interval (CI): 0.880–0.982), while both S100A9 (AUC: 0.791, 95% CI: 0.711–0.871) and CR1 (AUC: 0.747, 95% CI: 0.647–0.820) showed fair accuracy.