Indeed, the oncoprotein AML1-ETO, a fusion protein associated with acute myeloid leukemia (AML), competes with CBP-p300 for binding to the acidic LxxLL motif of E-proteins, a family of transcription factors that normally interact via their LxxLL motif with the KIX domain of CBP-p300 [134,135]. This evidence concerns the gene CREBBP and acute myeloid leukemia.