Therefore, decreasing H3K27me3 in the refractory EZH2 gain-of-function mutant (henceforth referred to as EZH2GOF) DLBCL cells with a small molecule inhibitor of EZH2 activity is one strategy to overcome the H3K27me3-mediated resistance to chemotherapy. This evidence concerns the gene EZH2 and diffuse large B-cell lymphoma.