IFN-γ transgenic mice have altered frequencies and numbers of myeloid progenitor cells. Bone marrow cells (A) or spleen cells (C) from transgenic or control mice were assayed to determine the frequency (left graph) and total number (right graph) of CFU-c– and CFU-GEMM–producing myeloid progenitors. (B) Bone marrow cells from transgenic or control mice were also assessed for the frequency and number of CFU-S progenitors. The data represent the mean ± SD of three replicates per group.