Update publication information. Metabolic syndrome (MS) is a cluster of risk factors that can lead to a disorder of energy utilization and storage and raises risk for heart disease and other health problems. Obesity is a prevalent metabolic disorder in the developed countries and in large parts of developing world that is one of main features of being diagnosed as MS. However, only part of obese people will develop into MS. Therefore, it is worthwhile to search more biomarkers implicated in metabolic syndrome that can help understanding the complex pathogenetic process of this disease better. In this study, we have performed a human serum proteomic analysis of MS using 2-D gel electrophoresis and liquid chromatography/tandem mass spectrometry.