Subsequent cytofluorimetric analysis gated on the BMMC population (consisting of approx. 90% AML blasts) performed under more sensitive conditions (calibrated cytofluorimetry; Figure 2A) revealed a mean expression of 130 and 230 copies per cell of CD33 and CD123, respectively, in this population of cells. The gene discussed is CD33; the disease is acute myeloid leukemia.