E2F1 regulates inflammation. Bone marrow–derived macrophages from B6;129E2F1−/− mice produce less IL-12 (p40) (A) and TNF-α (B) than B6 × 129 F2 control mice (three pools of two mice each) 5 hours after stimulation with LPS, lipotechoic acid (LTA), Pam 3 Cys-Ser-(Lys) 4 (Pam3Cys), poly (I:C), zymosan, and CpG DNA. *P < 0.05 by two-tailed t test. (C) B6;129E2F1−/− mice produce less serum TNF-α, IL-6, and IL-1β than B6 × 129 F2 control mice 3 hours after systemic LPS (n = 12 in each group). Two-tailed t test: P < 0.01 for TNF-α, P < 0.05 for IL-6, and P < 0.005 for IL-1β.