In B-cell lymphomas, heterozygous gain-of-function mutations of residues within the catalytic SET domain of EZH2 occur in diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma, and result in enhanced H3K27 trimethylation and transcriptional repression [28]. Here, EZH2 is linked to B-cell non-Hodgkin lymphoma.