Fig. 8. Effect of siRNA on the GPA cell-surface expression of CD34⁺ cells cultured in erythroid differentiation conditions. CD34⁺ progenitor cells were cultured for 3 days under conditions optimized for erythroid-cell growth and maturation in the presence of either an siRNA specific for NACA or an irrelevant siRNA. The GPA cell-surface marker was analysed by flow cytometry in the absence of siRNA duplexes (left), in the presence of an siRNA specific for NACA (center) and in the presence of an irrelevant siRNA (right). The numbers (insert) correspond to the proportion of GPA-positive cells.