To determine whether myeloid cells contribute to MCP-1 production during innate immune responses, we induced peritonitis in MCP-1flox/flox and LysMCre+, MCP-1flox/flox mice by i.p injection of TG or zymosan A and examined the concentration of MCP-1 and the number of accumulated macrophages in peritoneal exudates. Here, CCL2 is linked to peritonitis.