CREBBP and diffuse large B-cell lymphoma: In order to test the consequences of the many CREBBP amino changes associated with FL and DLBCL on KMT2D acetylation, we used expression constructs for seven common missense HAT mutant alleles, as well as a recurrent in-frame deletion located C-terminal to the HAT domain (ΔS1681) and, as control, a HAT truncation mutant to perform transient cotransfection assays in 293T cells (Fig. 7A).