Granulocyte-macrophage colony-stimulating factor (GM-CSF), which is increased in human MPN38,39 and murine MPN BM (Figure 3B), doubled CD24 expression in mouse MPN neutrophils; this was not the case for other JAK-STAT-dependent (G-CSF) or -independent (M-CSF, interleukin-1β) cytokines (Figure 3C). This evidence concerns the gene CSF2 and myeloproliferative disorder.