Taken together, our new data along with the published observation provide further evidence for a central role of SAA in adipocyte-macrophage cross-talks in obesity: 1) SAA increases IL-6 and IL-8 production by adipocytes as well as the chemokine MCP-1, which recruits circulating monocytes into the adipose tissue; 2) SAA increases IL-6, IL-8 and TNFα production by immune cells; 3) SAA displays direct chemoattractant activity in the presence or absence of hyaluronan complexes [15], [33], [41]–[44]. Here, CCL2 is linked to obesity due to melanocortin 4 receptor deficiency.