KIR2DL4 and acute myeloid leukemia: Furthermore, the receiver operating characteristic (ROC) curve indicated that KIR2DL1, KIR2DL3 and KIR2DL4 expression exhibited good predictive power to discriminate AML from normal samples, with area under the curve values of 0.877 (95% confidence interval [CI] = 0.836–0.917), 0.925 (95% CI = 0.893–0.957) and 0.913 (95% CI = 0.882–0.943), respectively (Figure 1F).