Differential cytokine gene expression in primary macrophages and neutrophils. Macrophages (A) and neutrophils (B) from wild-type and C/EBPβ-deficient mice were harvested from peritoneal cavity and cultured either with (+) or without (−) LPS (100 ng/mL, 4 hours). Total RNAs were isolated, and expression of cytokine genes was quantified by real-time RT-PCR as a ratio of these transcripts/18S transcripts, and wild-type LPS-untreated samples are calculated as 1. ■ and □ show wild-type and C/EBPβ-deficient mice, respectively. Results represent the mean plus or minus SD.