Mig regulates hematopoiesis through different signaling pathways in MSCs and HPCs. (A) Mig activated p70 S6K and Erk in MSCs. (B) Mig inhibited STAT5 phosphorylation in CD34⁺ HPCs. Signaling pathways of MSCs and HPCs were examined after stimulation with 20 ng/mL Mig for 30 minutes. Shown are means + SEM of the mean fluorescent intensities (MFI; per 10 μg of total protein) of 2 independent, duplicate experiments (*P < .05). (C) Freshly isolated CD34⁺ cells (8000) were incubated for 1 week. GM-CSF induced the expansion of CD45⁺ cells compared with medium alone (#P < .001). Mig significantly reduced the GM-CSF–dependent CD45⁺ expansion, and the effect was reversed by anti-CXCR3 monoclonal antibody (**P < .001) compared with GM-CSF + Mig. Pictures of cell pellets after incubation were taken, and the dimensions were measured (total magnification, ×100; objective lens' magnification, ×10). Bars represent means + SEM of 2 independent, quadruplicate experiments.