GM-CSF/IL-3–deficient macrophages produce increased inflammatory cytokines in response to LPS stimulation. (A). Real-time PCR analysis shows increased levels of p19, p35, and p40 in GM-CSF/IL-3–deficient macrophages compared with wild-type control mice. (B). GM-CSF/IL-3–deficient macrophages secrete elevated levels of p40 protein compared with wild-type macrophages. Shown are 3 animals per group. Similar results were observed in 3 independent experiments. Error bars refer to the standard deviations for the 3 samples in each group.