Inhibition of TCR signaling pathway negative regulators by DNA hypermethylation. (A) Venn diagram showing 22 genes that overlap between samples with HTLV-1–specific hypermethylated DMPs and those with expression decreased twofold or more in HTLV-1–infected cells in the gene expression data set, GSE55851. (B) Unsupervised hierarchical clustering analysis of the 22 extracted genes, using DNA methylation data (CpG probes used for unsupervised hierarchical clustering analysis are listed in supplemental Table 2). (C) Average β values of the 45 probes for the 22 extracted genes in each cell subpopulation from individuals and HTLV-1–infected T-cell lines. (D) Representative flow cytometric analysis of THEMIS, LAIR1, and PD-1, showing the amount of protein expression in P (blue), D (yellow), and N (red) cell subpopulations from a patient with smoldering ATL (left) and the average mean fluorescence intensity (MFI; right).