KMT2A::ARHGEF12 is an extremely rare fusion with only 8 patients reported in the literature (4 AML, 3 acute lymphoblastic leukemias and 1 high grade B cell lymphoma) and seems to correlate with therapy-related hematological malignancies with poor prognosis [2, 3]. The gene discussed is ARHGEF12; the disease is acute myeloid leukemia.