The infiltrated monocytes/macrophages do not die by apoptosis. WT and Mac-1^-/- macrophages were injected intraperitoneally with TG for 4 days and then were injected intraperitoneally with PBS or LPS. Four hours later, the peritoneal macrophages were assessed for apoptosis by DNA fragmentation (A) and by dual-color FACS analysis using annexin V and 7-AAD (B-C), where annexin V stains apoptotic cells and the cell-impermeable fluorescent dye 7-AAD stains necrotic cells. Additionally, the lavaged WT (B) and Mac-1^-/- (C) macrophages were cultured in vitro for 0 (B, Ci) and 20 (B, Cii) hours in the absence or 4 (Biii) and 20 (Biv, Ciii) hours in the presence of LPS plus the mitogen-activated protein kinase (MAPK) inhibitor SB202190, and then analyzed for apoptosis. The inserts shown are the percentages of different populations. The data shown are representative of 2 independent experiments.