The MPN developed on a FOXM1-overexpressing background showed significantly higher resistance to standard chemotherapy, as evidenced by increased leukemic burden in the BM, spleen, and blood by GFP assessment (Figure 2, B and C, and Supplemental Figure 2C) and by larger spleen size (Supplemental Figure 2D). This evidence concerns the gene FOXM1 and myeloproliferative disorder.