NPM1 and acute myeloid leukemia: To observe whether such a locus-specific accumulation of p300 after BETi was reproducible in other AML subtypes, we performed ChIP-Seq for BRD4 and p300 (again at 24hr following DMSO/BETi) in a completely independent BETi-sensitive AML cell line—OCI-AML3 (NPM1-mutated).