EZH2 and diffuse large B-cell lymphoma: Gain-of-function mutations affect the coding region of enhancer of zeste homologue 2 (EZH2), a histone lysine N-methyltransferase enzyme, resulting in the increased silencing of multiple tumor suppressor genes, which promotes cell survival and proliferation, also an important hallmark of GCB DLBCL [29,30,31].