IFNγ impairs the proliferation and differentiation of myeloid progenitors in response to G-CSF. Absolute cell numbers derived from 1000 CMPs (A) and 1500 GMPs (B) after 3 days of culture with M-CSF or G-CSF with or without IFNγ. (C) Histograms showing CFSE dilution of CMPs and GMPs cultured for 3 days with M-CSF or G-CSF with or without IFNγ and absolute number of cells in each CFSE dilution peak of G-CSF–cultured (D) and M-CSF–cultured (E) CMPs and GMPs. (F) Representative plots showing CFSE dilution versus c-Kit or lineage expression of CFSE-labeled CMPs cultured for 3 days with M-CSF or G-CSF with or without IFNγ. Data in panels A, B, and D represent means ± SD from triplicate cultures and all data are representative of 3 independent experiments. *P < .05; **P < .01; ***P < .001.