Inactivating mutations in histone acetyltransferase (HAT) genes CREBBP and EP300 were identified in approximately 30% of DLBCL cases [12, 13], whereas mutations in other HAT family members (TIP60, MOZ, CLOCK, NCOA2, NCOA3) exhibited lower frequencies (< 5%) [17, 18]. This evidence concerns the gene CREBBP and diffuse large B-cell lymphoma.