Mig inhibits BM proliferation through CXCR3 in vivo and in vitro. Normal mice (n = 6) were injected once daily for 5 consecutive days with 15 μg/kg recombinant Mig protein or with PBS as control after 5-FU treatment. BMNCs and lin⁻ cells were collected within 24 hours after the final injection, and their cell cycle status was analyzed by flow cytometry. (A-B) Both BMNCs and lin⁻ cells of WT mice were depressed significantly during the S phase; however, in CXCR3 KO mice (C; n = 4), Mig did not interfere with the cell cycle. (D-E) BMNCs were collected from healthy WT or CXCR3 KO mice for colony assays with PBS (control) or 30 ng/mL recombinant HuMig (Mig). Mig significantly inhibited colony formation in WT mouse but had no effect on KO mouse. *P < .05, **P < .01. Shown are means + SEM of 4 separate tests in WT mice and 3 in KO mice.