Rearrangements of the myeloid/lymphoid or mixed lineage leukemia (MLL) gene (also known as KMT2A) on chromosome 11q23 are seen in approximately 2–10% of AML cases, are enriched in therapy-related AML, and carry a poor prognosis (Schoch et al., 2003; Tallman et al., 2019). This evidence concerns the gene KMT2A and acute myeloid leukemia.