Time course of c-Mpl and CD34 expression on CD13⁺ cells grown by SCF + GM-CSF from JCML CD34⁺CD38^high cells. The cells generated by the JCML CD34⁺CD38^high cells in the presence of SCF + GM-CSF were labeled with anti–c-Mpl MoAb, and then stained with FITC-conjugated GAM. After treatment with mouse serum, the cells were stained with PE-conjugated CD13 MoAb and PE-Cy 5–conjugated CD34 MoAb. Surface marker expression was analyzed on days 5, 8, and 12. The quadrants were determined by the negative controls using isotype-matched Ig.