Peripheral blood parameters of Fac −/− andFac +/+ mice. (A) Red blood cells (RBC), (B) white blood cells (WBC), and (C) platelets. Measurements were made in mice from a 50%/50% 129ag/129R1 background treated with repeated MMC injections (0.3 mg/kg). Results are expressed as the mean number of cells measured in 4 mice. Mice used in this experiment died between 6 and 8 weeks of treatment. All control mice survived for more than 12 weeks before being killed for histological analysis. Fac −/− mice that received a single MMC injection or Fac +/− mice gave similar results as control Fac +/+ mice. Each point represents the mean ± SEM of four separate determinations. The absence of SEM bars represents values too low to appear in the graph.