KMT2A and acute myeloid leukemia: However, we suggest that this observation is a consequence of the allocation of patients with different molecular aberrations to particular AML risk groups (i.e., PML-RARa+ patients with the lowest HOXA gene expression levels being assigned to the SR group and MLL+ cases with the highest expression levels of HOXA genes being allocated to the HR group) and not an independent prognostic factor.