Consistent with the ability of n-3 PUFA to reduce the percentage of adipose tissue infiltrating macrophages during obesity (Figure 2), adipose mRNA expression of MCP-1, a macrophage chemotactic signal, was reduced by 44% in the HF-FO group relative to HF alone (P = 0.001). This evidence concerns the gene CCL2 and obesity due to melanocortin 4 receptor deficiency.