We compared the protein expression level of p-STAT5/STAT5, Pim-1 and CXCR4 among the FLT3-ITD-mutated, FLT3-wt and normal control groups using Western blotting to further examine whether CXCR4 expression in leukemia cells is regulated by FLT3-ITD mutations. The gene discussed is PIM1; the disease is leukemia.