Importantly, mice lacking the Irf8 gene (Irf8-/- mice) develop a chronic myelogenous leukemia (CML)-like syndrome, in which there is a disproportionate expansion of neutrophils at the expense of monocytes/macrophages [8], [9], [10]. Here, IRF8 is linked to chronic myelogenous leukemia, BCR-ABL1 positive.