CBFB and acute myeloid leukemia: For the group of AML with defining genetic abnormalities, it now recognizes—apart from known fusions, e.g., PML::RARA, RUNX1::RUNX1T1 or CBFB::MYH11—rearrangements involving KMT2A, MECOM, and NUP98, irrespective of the fusion partner, as disease-defining, even with blast counts below 20% [18].