GFAP was expressed at very low level and its expression level in AML patients (median, 2.2×10−7; range, 0.5×10−7-2.2×10−6) was significantly lower than that in control group (median, 6.7×10−7; range, 0.9×10−7-3.9×10−6; P=0.004). The gene discussed is GFAP; the disease is acute myeloid leukemia.