In particular, we observed that CD123+ mature haematopoietic cells (CD38+ CD34−) from HDs, although they were detected with low frequency, were characterized by a higher MFI and GeoMean than AML cells (Fig. 1B, p < 0.001 and 1C, p < 0.001), whereas undifferentiated CD38− CD34+ leukaemic cells showed a higher CD123 MFI and GeoMean than HD haematopoietic cells (Fig. 1B, p = 0.003 and 1C, p = 0.04). This evidence concerns the gene CD34 and acute myeloid leukemia.