DNMT3A and acute myeloid leukemia: In 2011, we discovered recurrent loss-of-function mutations of BCOR in AML (about 4% of cases with normal karyotype) and found that they were usually mutually exclusive of FLT3-ITD and NPM1 mutations, co-occurred with DNA methyl transferase (DNMT3A) mutations and were associated with a poor outcome [9].