IRX5 and acute myeloid leukemia: ,23 Thus, in human AML cases with high IRX3 expression there are two patterns of histone acetylation within the IRX3 TAD: in FTO-lncAMLlow cases increased H3K27Ac is found surrounding IRX3, CRNDE, and IRX5 whereas in FTO-lncAMLhigh cases there is in addition significant H3K27Ac ChIP signal within distal intronic sequences of FTO.