Effects of mIL-3, hG-CSF, and hTPO on megakaryocyte size in Mk colonies. Three independent experiments were analyzed to generate this figure. The horizontal bars in each group represent the mean perpendicular diameters of megakaryocytes in Mk colonies. The numbers of measured megakaryocytes are presented in parentheses. The megakaryocytes from Mk colonies supported by hG-CSF were significantly larger than those in case of mIL-3, but smaller than those in case of hTPO (P < .001, for both).