CCL2 and Insulin resistance: Murine models that disrupt macrophage expression of CCR2, an important receptor for chemotaxis, demonstrate reduced weight gain, insulin resistance, and liver fat accumulation despite consumption of a high-fat diet (HFD) [21], while transgenic overexpression of monocyte chemoattractant protein 1 (MCP-1) leads to the recruitment of macrophages into AT and the development of insulin resistance [22].