Activating mutations in the EZH2 gene are frequently observed in diffuse large B cell lymphoma and are strongly associated with the lack of MHC-I/MHC-II expression and reduced T-cell infiltration; treatment with EZH2 inhibitors (EZH2i) restored MHC expression by de-repression of NLRC5 and CIITA promoters in EZH2 mutant cells [44]. The gene discussed is EZH2; the disease is diffuse large B-cell lymphoma.