HDAC9 and diffuse large B-cell lymphoma: For example, in B cell non-Hodgkin lymphoma (B-NHL), aberrant expression of the HDAC9–BCL6 complex contributes to lymphomagenesis.119 In follicular lymphoma (FL) and diffuse large B cell lymphoma (DLBCL), CBP mutations disable the acetylation of the HDAC9–BCL6 complex and lead to unopposed deacetylation by the BCL6–SMRT–HDAC3 complex at enhancers of B cell immune response genes, which promotes lymphomagenesis.120 In miR-155-induced pre-B cell leukemia/lymphoma, HDAC4 in complexes with BCL6 plays an important role in suppressing leukemogenesis.121