The dysregulation of H3K27 trimethylation (H3K27me3) is important in human tumorigenesis (25), and some reports have shown that mutant EZH2 increases the level of H3K27me3 in follicular lymphoma, germinal center B-cell type diffuse large B-cell lymphomas (21, 24, 41) and metastatic skin melanoma (42). This evidence concerns the gene EZH2 and diffuse large B-cell lymphoma.