IL18 and hemophagocytic syndrome: In addition, the receiver operating curve (ROC) was used to analyze the evaluation value of blood IL-18 level in the prognostic outcome of HLH, and the results showed that the area under the curve (AUC) was 0.6813 (95% CI: 0.5365-0.8260, p = 0.0189), the cut-off value is 45.75 ng/L, and the corresponding sensitivity and specificity are 59.09% and 80.00%, respectively.