In this study, therefore, we investigated the changes in serum levels of the inflammatory markers YKL-40 and MCP-1 in the fasting state and during mixed meal tests in a group of obese patients with type 2 diabetes and a group of obese subjects with normal glucose tolerance (NGT), previous to and after (1 week (wk), 3 months (mo), and 1 year (yr)) RYGB. This evidence concerns the gene CCL2 and type 2 diabetes mellitus.