Impaired expression of H3K4ac1 and H3K4ac3 was commonly observed in lymphoma.372 The overexpression of HDAC1 and HDAC2 was discovered in DLBCL compared to their expression in normal lymphoid tissues.373 The inhibition of HDAC1 and HDAC2 was found to impede Eμ-myc B-cell lymphoma development via apoptosis stimulation and proliferation repression, indicating the oncogenic role of HDAC1 and HDAC2.374 HDAC1 expression was found to be significantly related to worse prognosis in DLBCL patients and PTCL-NOS patients.375 HDAC3 overexpression was pathogenic when CBP mutations were present. This evidence concerns the gene HDAC2 and mature T-cell and NK-cell non-Hodgkin lymphoma.