In addition, genetic mutations, alternative splicing and altered expression of chromatin regulatory proteins such as CHD4 have been identified in MLLr AML samples after lineage switching10, and mutations in components of a MLL related complex, KMT2C/D-UTX, can lead to resistance to menin inhibitors in cell line and animal models17. The gene discussed is KMT2A; the disease is acute myeloid leukemia.