Analysis of EBV copy number and methylation in plasma DNA from clinical specimens. EBV copy number and EBV methylation index from plasma of patients with nasopharyngeal carcinoma (A-B), Kaposi sarcoma (C-D), and EBV(−) and EBV(+) HL (E-F). Scatter plots with mean and standard deviation presenting EBV DNA copy number on the left and the percentage of EBV DNA binding to beads (methylation index) on the right. The results of a 1-tailed Student t test are indicated. ****P ≤ .0001.