Classification of NK cell–type CAEBV based on the DNA methylation status. (A) Unsupervised hierarchical clustering of promoter-associated CpG island methylation profiles in NK cells from in-house samples (NK cell–type CAEBV, n = 32; IM, n = 4; non-EBV–IM-like, n = 2; healthy volunteers, n = 4) and deposited data (ENKTL, n = 15; normal NK, n = 21). Case/control, disease, and cluster are indicated in different colors (top). DNA methylation heat map of the 3000 most variable probes associated with the promoter (bottom). (B) Principal component analysis of the samples described in panel A using the 3000 most variable probes associated with the promoter. (C) Kaplan-Meier OS curves of 12 CIMP-positive and 20 CIMP-negative CAEBVs. The table below the plot indicates the number of patients at risk at each time point. (D) Forest plots of multivariate analyses of OS performed using the Cox proportional hazard model (hazard ratio ± 95% confidence interval [CI]). CIMP status and known clinical prognostic factors were included in the model. AIC, Akaike information criterion; PC1, principal component 1; PC2, principal component 2.