In our clinical practice, we noted cases of AML with various RUNX1 lesions (beyond RUNX1::RUNX1T1 fusion and RUNX1 mutations) with aberrant expression of several B-cell markers, mimicking mixed-phenotype acute leukemia (MPAL)-B/myeloid at diagnosis [7]. This evidence concerns the gene RUNX1T1 and acute myeloid leukemia.