Indeed, KMT2A-rearranged AML tends to have a maturing myeloid phenotype (M4 and M5 in the French–American–British classification) (Tien et al. 2000), and, in normal hematopoiesis, expression of IRF8 is highest in granulocyte–monocyte progenitors (Supplemental Fig. S13). Here, IRF8 is linked to acute myeloid leukemia.