CREBBP and diffuse large B-cell lymphoma: Interestingly, CREBBP mutations in human FL/DLBCL, as well as in murine lymphomas, have been associated with a huge reduction in MHC class II expression, together with a defective antigen presentation and a decreased CD4pos T cell infiltration, showing how a single genetic hit can affect the composition of the lymphoma niche (87, 88).