IRF8 protein expression in granulocytes, mast cells, and their progenitors. (A) Using Irf8^Irf8Gfp/WT mice, IRF8 protein expression was determined as GFP fluorescence intensity in each indicated cell population gated by cell surface antigen staining using flow cytometry. Data are representative of 2 independent experiments with similar results. (B) Irf8 transcript levels were measured by RT-qPCR. Values in the bar graphs are means ± standard deviations from triplicate samples. Analysis of IRF8 protein expression in other hematopoietic progenitor populations has been reported elsewhere.^26,27