Trade-off of sensitivity vs specificity of plasma EBV copy number as a discriminator of EBER-ISH status, plotted as a receiver operating characteristic (ROC) curve. Area under the ROC curve is 0.94 (95% confidence interval 0.86-1.01). Sensitivity and specificity are optimized at plasma EBV cutoff of >60 viral copies/100 µL plasma (★ on curve).